The Advanced Photon Source is a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357.

Advanced Photon Source Five-Year Facility Plan

March 31, 2015

The mission of the U.S. Department of Energy’s Advanced Photon Source at Argonne National Laboratory is to enable internationally leading research and development by safely operating an outstanding hard x-ray synchrotron radiation user facility accessible to a broad and diverse spectrum of researchers, and to support the scientific and technical directions of the U.S. Department of Energy, including development of new light source technologies.

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Table of Contents 1 Executive Summary ..................................................................................................................... 5

2 Introduction .................................................................................................................................. 6

3 Facility Goals ................................................................................................................................ 8

4 National and International Context for Storage Ring Light Sources ..................................... 8

4.1 International storage rings ................................................................................................................. 8

4.2 U.S. storage rings ............................................................................................................................... 9

5 Opportunities................................................................................................................................ 9

6 X-ray Operations and Improvements ...................................................................................... 10

6.1 X-ray Science for Chemistry ........................................................................................................... 11

6.2 X-ray Science for Materials ............................................................................................................. 17

6.3 X-ray Science for Biological and Environmental Studies ............................................................... 24

6.4 Enabling Technologies for X-ray Science ....................................................................................... 33

6.4.1 Optics, Detectors, Data Collection and Analysis ....................................................................... 33

6.4.2 Beamline Engineering ................................................................................................................ 38

6.4.3 R&D for X-ray Techniques Greatly Improved with the Proposed APS Upgrade ..................... 39

7 Accelerator Operations and Improvements ............................................................................ 44

7.1 Accelerator Reliability ..................................................................................................................... 45

7.2 Accelerator Improvements............................................................................................................... 45

7.3 Accelerator R&D to Advance New Concepts and Next-Generation Light Sources........................ 46

8 Mission Readiness ...................................................................................................................... 47

9 Infrastructure, General Operations, Support, and Improvements ....................................... 47

10 Human Capital and Workforce Development ........................................................................ 48

11 User Processes and Scientific Access ....................................................................................... 48

11.1 Outreach to Users .......................................................................................................................... 49

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11.2 User Support/Access ...................................................................................................................... 49

11.3 User Training ................................................................................................................................. 50

11.4 Proposal Review Process ............................................................................................................... 50

11.5 Training the Future Science Generation ........................................................................................ 50

12 Input and Review Mechanisms for the APS 5-Year Facility Plan ........................................ 51

Appendix 1: Beamlines and Enabling Technologies ..................................................................... 52

Table 1. Upgrades and Improvements to APS-Operated Beamlines ....................................................... 52

Table 2. Upgrades and Improvements in Enabling Technologies for X-ray Science .............................. 56

Appendix 2: User Data .................................................................................................................... 58

On the cover: Aerial photo of the Advanced Photon Source by John Hill, Tigerhill Studio. Background: A high-energy x-ray diffraction pattern from a single grain of icosahedral rare-earth-cadmium quasicrystal, taken with x-ray beam from the APS superconducting undulator at X-ray Science Division beamline 6-ID-D and used on the cover of Nature Materials. Courtesy of Alan Goldman, Andreas Kreyssig, Mehmet Ramazanoglu, and Paul Canfield (Ames Laboratory, Iowa State University).

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1 Executive Summary The Advanced Photon Source (APS) at Argonne National Laboratory is a U.S. Department of Energy Office of Science-Basic Energy Sciences scientific user facility. The core mission of the APS is to serve the scientific community by providing high-energy x-ray science tools and techniques that allow users to address the most important basic and applied research challenges facing our nation, while maintaining a safe, diverse, and environmentally responsible workplace. The APS has been optimized to provide the nation’s highest-brightness hard x-rays (i.e., photon energies above 20 keV). This makes it ideally suited to explore the time-dependent structure, elemental distribution, and chemical, magnetic, and electronic states under in situ or in operando environments for a vast array of forefront problems in chemistry, materials science and condensed matter physics, and the life and environmental sciences.

Although a mature facility, the APS must continue to improve beamline performance to take full advantage of its existing source properties, as well as deliver new capabilities required by the large and scientifically diverse APS user community. This includes improving specific beamlines and end stations and continued optimization of the APS beamline portfolio, while maintaining the excellent reliability and availability of the APS accelerator and storage ring systems. Additionally, research challenges that require vastly brighter hard x-rays or higher coherent flux than the APS currently produces are now within reach because of revolutionary new storage ring lattice designs that dramatically reduce the stored electron beam emittance. The APS is currently developing plans for a major upgrade with such a multi-bend achromat (MBA) magnetic lattice that will increase x-ray beam brightness and coherent flux by 100 to 1,000 times over current values. Combined with the penetrating power of the hard x-rays produced by the APS, along with the time structure of the electron bunches in the APS storage ring, this proposed upgrade will make the APS ideally suited to meet the global science and energy challenges of the 21st century, by providing the time-resolved microscopy, imaging, scattering, and spectroscopy methods necessary to revolutionize our understanding of hierarchical architectures and beyond-equilibrium matter, and the critical roles of heterogeneity, interfaces, and disorder.

This “Advanced Photon Source Five-Year Facility Plan” charts the path over the next five years for the improvements and R&D that will maintain the APS position as the world-leading hard x-ray synchrotron source while simultaneously preparing for the proposed upgrade. This includes greater focus on high-energy x-ray methods and increased utilization of brightness and coherence to provide dramatically enhanced spatial and temporal resolution for all classes of experiments. A prioritized set of near- and long-term beamline investments is presented, derived from an assessment of scientific opportunities and the needs of the APS user community. This is followed by a description of R&D in enabling technologies for x-ray science that cut across all aspects of the APS beamline portfolio. Required directions in optics, detectors, data sciences, and beamline engineering are outlined. To optimally position the APS and its user community for the proposed upgrade, R&D must also commence on the set of x-ray science techniques that will be revolutionized by the improved source properties resulting from the new lattice. Therefore, development efforts are described for hard x-ray nanoprobes, phase contrast imaging, x-ray photon correlation spectroscopy, coherent diffractive imaging and ptychography, and nanoscale high-energy diffraction.

Accelerator operations plans must meet the current and future capability needs expected of a world-leading light source while maximizing efficiencies and delivering high beam availability to users. It is currently assumed that the present APS storage ring will stop operation approximately in the 2020s and be replaced by a MBA lattice. Thus, this facility plan aligns end-of-life plans for accelerator systems to maintain the very high level of APS performance and reliability, with R&D plans that take into account the long-term transition to a MBA lattice source. This is accomplished in three main areas: accelerator reliability, accelerator improvement, and accelerator R&D to advance new concepts and next-generation light sources.

Finally, this plan briefly describes additional activities necessary to address general maintenance and obsolescence issues (mission readiness), improvements for infrastructure and general operations, and user processes and scientific access including outreach and training.

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2 Introduction The Advanced Photon Source (APS) is a U.S. Department of Energy Office of Science (DOE-SC)-Basic Energy Sciences (BES) scientific user facility with a core mission to serve and grow the scientific community that utilizes synchrotron x-rays by providing this critical and scientifically diverse user community with the x-ray science tools and techniques that they require, while maintaining a safe, diverse, and environmentally responsible workplace. The APS is one of five x-ray light sources that are operated as national user facilities by the DOE-SC (there are four storage rings: the APS, the Advanced Light Source [ALS], the Stanford Synchrotron Radiation Lightsource [SSRL], and the National Synchrotron Light Source II [NSLS-II]; and one free-electron laser (FEL): the Linac Coherent Light Source [LCLS]). Of the four storage rings, the APS operates at the highest electron energy (7 GeV, 100 mA), and it has been optimized to be the source of the nation’s highest-brightness hard x-rays (i.e., photon energies above 20 keV). High-brightness hard x-rays can penetrate deeply into materials and be concentrated efficiently in a small spot. This combination enables in situ, real-time studies of internal structure and chemical state in actual environments and under relevant operating conditions. The APS also is the largest of the DOE light source facilities, both in the size of the facility and its user community. The APS facility is comprised of an accelerator complex and storage ring, beamlines, and supporting laboratory and office space. There are currently 66 operating x-ray beamlines; of these, 34 are operated directly by the APS (Appendix 1) under operations funding from DOE-SC-BES. An additional beamline, the Sector 26 hard x-ray nanoprobe, is operated jointly by the APS and the adjacent BES scientific user facility, Argonne’s Center for Nanoscale Materials (CNM). Finally, Sector 23 is operated by the APS as a national facility for structural biology, with funding from the National Institute of General Medical Sciences and National Cancer Institute of the National Institutes of Health.

The beamlines outside of this portfolio are operated by collaborative access teams, or CATs. The APS has by far the largest participation of operational partners at any U.S. light source. These very diverse collaborations of industry and academia operate according to a number of different models, and to the benefit of the user community bring in substantial non-BES funding. The APS provides photons and some minimal direct operations support, with recovery of certain costs, in return for each CAT awarding a fraction of its beam time to General Users. Normally, this fraction is 25%, with the exception of CAT-operated beamlines that serve as national resources and that award 100% of their time to General Users. The specialized nature of beamlines and end-station instrumentation, including detectors and optics at several of the CATs, also enables complementary facilities that allow the APS community to provide the broadest reach and to build world-leading capabilities in key fields such as high-pressure research, dynamic compression science, and the biological and life sciences.

Access to the APS is obtained via a scientific peer review process and is heavily over-subscribed. In FY 2014, the APS supported 5,017 unique users (on-site and remote/mail-in) from 49 states, Puerto Rico, the District of Columbia, and over 30 nations, conducting research that spanned the full range of fundamental and applied sciences across fields including materials science, biological and life sciences, geosciences, planetary science, environmental science, engineering, chemistry, and physics. Users of this facility come from academia, industry, and government institutions. As the APS user program has grown, so has its publication output grown, with more than 1,700 papers published in FY 2014 as of this writing. Of those, more than 1,500 are peer-reviewed journal articles, with 24% of those in DOE-defined high-profile journals (Advanced Materials, Angewandte Chemie International Edition, Applied Physics Letters, EMBO Journal, Cell, Environmental Science and Technology, Journal of the American Chemical Society, Nano Letters, Nature Chemical Biology, Nature Chemistry, Nature Geoscience, Nature Materials, Nature Nanotechnology, Nature Photonics, Nature Physics, Nature Structural and Molecular Biology, Nature, Physical Review Letters, Proceedings of the National Academy of Sciences USA, and Science). Macromolecular crystallographers utilizing APS x-ray beams place more protein structures in the Protein Data Bank (http://biosync.sbkb.org/ stats.do?stats_sec=RGNL&stats_focus_lvl=RGNL&stats_region=Americas) than do researchers at any other light source in the world.

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Another critical component for scientific productivity is operation of the APS electron accelerator for a target of 5,000 hours per year with extremely high availability (98% in FY 2014) and reliability (96 hours Mean Time Between Faults in FY 2014). These are exceptional statistics for a facility of such complexity and equal to, if not better than, any similar facility worldwide. The APS does all of this within a safe and secure environment for its staff and users.

The APS resides within a major multidisciplinary national laboratory – this creates unique opportunities for synergy and provides a powerful research ecosystem for the development and use of x-ray science, creating an environment that fosters scientific creativity and innovation, and helps users expedite discovery. In many cases, users of the APS also work with other members of Argonne’s scientific community in a variety of disciplines; work side-by-side with resident industry x-ray users; or share ideas with members of DOE hubs and initiatives such as the Joint Center for Energy Storage; and access other user facilities and centers such as the Argonne Leadership Computing Facility and Center for Nanoscale Materials.

The APS produced first x-ray light in 1995, and became operational in 1996. Since then, a number of major advances have occurred in accelerator, storage ring, and beamline technologies and techniques. Combined, these advances have dramatically altered the landscape for x-ray science. In particular, research challenges that require vastly brighter hard x-rays or a higher coherent flux than the APS currently produces are now within reach because of new storage ring lattice designs that dramatically reduce the stored electron beam emittance. Therefore, the APS is now developing plans to install a multi-bend achromat (MBA) magnetic lattice into the existing storage ring tunnel that will increase x-ray beam brightness and coherent flux by 100 to 1,000 times (for energies above 10 keV) over current values. This upgrade of the storage ring is a cost effective approach to a “fourth-generation” storage ring as it will reuse much of the existing accelerator and beamline infrastructure.

While the detailed science case and technical design for this proposed upgrade are presented elsewhere, the brightness and coherence increase from the APS Upgrade in the hard x-ray region of the spectrum will revolutionize imaging, microscopy and nanobeam science, high-energy methods, and high-wavenumber scattering techniques. The penetrating x-ray probes produced by the upgraded APS will transform in situ, real-time studies of internal structure during synthesis and function in actual environments and under relevant operating conditions, across a hierarchy of length scales from the atomic to the macroscopic. They will also enable time-resolved studies of dynamics over a wide range of time scales from many seconds to less than a nanosecond, allowing relationships between structure and function to be observed. This proposed upgrade will help to maintain the APS’s world leading position in the hard x-ray community for many years to come.

However, the proposed APS Upgrade is still many years in the future. In the interim, the APS must continue to increase beamline performance to take full advantage of the existing source, as well as deliver new capabilities to the user community and meet the scientific needs embodied in our nation’s future challenges and the DOE mission — which are inextricably entwined — and to provide the highest level of support to APS users. This will include improvements to specific beamlines and end stations, as well as continued optimization of the APS beamline portfolio, while maintaining the excellent reliability and availability of the APS accelerator and storage ring systems.

This “Advanced Photon Source Five-Year Facility Plan” is driven by the above responsibilities. This document comprises an outline of improvements and R&D to be undertaken by APS operations during the next five years, employing a two-pronged approach: keeping the APS a world-leading hard x-ray synchrotron source while simultaneously preparing for the proposed upgrade. To achieve this goal, the APS must invest in aging accelerator and beamline infrastructure while developing innovative capabilities and continuing to drive efficient mission execution. By creating a synergy between today’s improvements and tomorrow’s needs, the APS will enable operational capabilities for the next five years and continue to grow a scalable, forefront science program that will smoothly transition to take advantage of an upgraded

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accelerator source. The improvements described here leverage APS core capabilities, particularly in the areas of in situ and in operando studies. Although this “Advanced Photon Source Five-Year Facility Plan” is primarily focused on the APS-operated, BES-funded beamlines, key developments for other beamlines are included in this plan, because these beamlines function as complementary assets to the BES program at the APS. For example, the large (and growing) life and environmental sciences communities at the APS also will leverage diverse assets to improve imaging and macromolecular crystallography capabilities.

Objectives described in this plan are comprehensive and have gone through a full facility-wide prioritization process for resource allocation. However, for beamline investments, prioritization is a continuing process based on user needs and trends, and will necessarily involve ongoing deep engagement with the user community and other stakeholders.

3 Facility Goals The APS has developed the following facility goals in order to fulfill its mission:

1. Operate a world-leading, highly reliable, high-brightness, hard x-ray user facility to enable outstanding science by users and staff; this requires maintaining clear lines of communication with users and partners in order to continually develop and deploy forefront capabilities and the necessary capacity to address scientific need

2. Increase capabilities of the APS by developing and implementing enhanced and/or novel accelerator and x-ray technologies; this includes rebuilding the APS storage ring with a MBA design and high stability to provide the first fourth-generation, hard x-ray storage ring source in the U.S.; developing next-generation undulators; and developing and instrumenting advanced beamlines that fully exploit the new, high-brightness source

3. Enable continued progress in light source technologies and their utilization in order to maintain the world leadership of the suite of U.S. DOE light sources

4. Assure the safety of facility users and staff

5. Maintain a world-class organization that is diverse, inclusive, and focused on innovation, and provide a rewarding environment for staff and users that fosters professional growth

The APS will achieve these goals by advancing strategies coupled to investment in the following areas:

1. X-ray operations and improvements, and research and development on x-ray techniques, optics, detectors, and data sciences

2. Accelerator operations and improvements, and research and development on new concepts and next generation light-source technologies

3. Mission readiness

4. Infrastructure, general operations, support, and other miscellaneous improvements

5. Human capital and workforce development

4 National and International Context for Storage Ring Light Sources

4.1 International storage rings Even though more than 70 light sources exist worldwide in more than 25 countries, the global demand for research time still outweighs availability. Several new facilities will become operational or be upgraded over the next decade, including ones based on next-generation MBA lattices.

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The hard x-ray facilities comparable to the APS are the European Synchrotron Radiation Facility (ESRF; 6 GeV, 200mA, εx = 4 nm•rad) in France, PETRA III (6 GeV, 100mA, εx = 1 nm•rad) in Germany, and SPring-8 (8 GeV, εx = 3.4 nm•rad) in Japan. Both ESRF and SPring-8 were built at about the same time (early-to-mid 1990s) as the APS. Both ESRF and SPring-8 are moving toward incorporating MBA lattice upgrades. The ESRF upgrade has been approved and is nearing start of construction, while SPring-8 is in the early planning stages. MAX-IV (3 GeV, 500mA, εx = 0.30 nm•rad) in Sweden and Sirius (3 GeV, 500mA, εx = 0.28 nm•rad) in Brazil, both featuring MBA lattices, are anticipated to come on-line in 2016 and 2018, respectively. It also appears possible that additional facilities in Russia and China will emerge in the next decade.

The APS (with its current accelerator complex) is projected to stay heavily oversubscribed and unable to fully provide the scientific capabilities that are on the horizon and that will be demanded by U.S. users. Furthermore, all 3+-GeV light sources, be they third-generation, enhanced with damping wigglers, or based on MBA lattices, offer stiff competition to or even surpass the existing APS for science requiring bright, coherent beams. Therefore, a future upgrade of the APS remains an imperative.

4.2 U.S. storage rings The U.S. has four x-ray storage ring sources operated as national user facilities by the DOE: APS (7 GeV, 100 mA, εx = 3.1 nm•rad); ALS (1.9 GeV, 500 mA, εx = 2 nm•rad), SSRL (3 GeV, 300-500 mA, εx = 10 nm•rad); and the newly-operating NSLS II (3 GeV, 500 mA, εx = 0.55 nm•rad). (The sole U.S. x-ray FEL, the LCLS, is being upgraded via the LCLS-II project.) In addition, the Cornell High Energy Synchrotron Source (CHESS, 5.3 GeV, 200 mA each electrons and positrons, εx = 145 nm•rad) is a high-intensity hard x-ray source supported by the National Science Foundation (NSF), which provides its users with synchrotron radiation facilities for research in physics, chemistry, biology, and environmental and materials sciences, and in macromolecular crystallographic studies. Finally, the Center for Advanced Microstructures and Devices (1.3 / 1.5 GeV, 300 / 150mA, εy = 150 nm•rad) is a research center funded by the State of Louisiana that provides low-energy synchrotron light for energy, environment, biomedical, and microfabrication research.

While each light source above provides a general range of standard x-ray capabilities for users, each of them also specializes in a specific energy range of the electromagnetic spectrum, enabling different types of science. As noted previously, the APS is optimized to be the nation's highest brightness source of hard x-rays in the energy range above 20 keV. The APS also has a very flexible storage ring fill pattern, routinely operating in 24-bunch mode with 153-ns spacing between bunches, 324-bunch mode with 11-ns spacing between bunches, and hybrid fill mode with a separation of 1.5 µs between the superbunch and remaining bunches. These parameters make the APS the leader in broad areas that require unique sample environments or high x-ray energies, including in situ, in operando, and high-pressure studies, as well as timing experiments outside the domain of FELs. The “Advanced Photon Source Five-Year Facility Plan” builds on these world-leading, and often unique capabilities to support a growing user base with expanding research needs.

5 Opportunities Given the landscape outlined in the previous section, the success of the APS hinges on identifying scientific and technical areas in which the APS can maintain leadership with appropriate investment, given that the APS accelerator characteristics are in some aspects not differentiated from other international sources. This requires careful evaluation of opportunities presented by the APS beamline portfolio (including those operated by CATs) and targeted investment in areas of light source technology in which the APS has strength.

In addition to a broad suite of foundational capabilities offered to users, the APS and its partners have established strengths in the following areas of x-ray science:

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• Macromolecular crystallography, including the increasing use of microbeams and other approaches to determine the structure of difficult-to-crystallize systems

• High-pressure science and dynamic compression science

• Probing magnetism with hard x-rays

• X-rays in the fourth dimension: stroboscopic and pump-probe-probe-probe methods to create x-ray movies of the dynamics of complex systems

• Three-dimensional (3-D) microscopy with elemental and chemical specificity

• Analysis of complex materials structure from Ångstroms to microns, including high-energy diffraction microscopy, tomography, and scattering (pair distribution function, or PDF; wide-angle x-ray scattering, or WAXS; small-angle x-ray scattering, or SAXS; grazing incidence small-angle x-ray scattering, or GISAXS; and ultra-small-angle x-ray scattering, or USAXS) combined with spectroscopy

• Inelastic scattering in both high-energy resolution and resonant configurations

Similarly, the APS maintains core competencies in light source science and technology, with established strengths in the following areas:

Novel undulators including permanent-magnet and superconducting undulators, and fast switching electromagnet undulators

Advanced diagnostics, specifically the development of a grazing incidence x-ray beam position monitor (BPM) using fluorescence as a signal source, and development of rf-cavity based high-precision beam position monitors for FELs.

User-friendly computer codes for simulation and modeling of accelerators

Control system software: EPICS collaboration, control system of choice for very large projects (International Thermonuclear Experimental Reactor, European Spallation Source, LCLS-II, NSLS-II, etc.)

Free-electron laser theory, more specifically concerning x-ray FEL oscillators

The basis outlined above sets the stage for continued development over the next five years of x-ray science and light source directions driven by user scientific demand, aligned with revolutionary opportunities that will be enabled by the proposed upgrade of the APS to an MBA lattice. At a high level, this includes greater focus on high-energy x-ray methods, for which the APS has unique capabilities, and increased utilization of brightness and coherence to provide dramatically enhanced spatial and temporal resolution for all classes of experiments.

6 X-ray Operations and Improvements The user communities supported by the APS are wonderfully diverse. With this in mind, it is helpful to discuss directions in x-ray science for the next five years in terms of broad categories of chemistry, materials science and condensed matter physics, life and environmental sciences, and the supporting capabilities that are required for state-of-the-art beamline science. While this categorization does not capture all of the nuances of the myriad scientific and engineering disciplines making up the APS user base, it does provide a tractable framework under which responsibility can be assigned for all beamlines for x-ray operations and beamline improvements. For each category, a general introduction is given to the principal synchrotron x-ray methods utilized at the APS for the research area, followed by more detailed descriptions of specific thrusts that broadly summarize the scientific directions pursued by the APS’ user community. Next, the APS’ leading or unique experimental capabilities in the category are given. Together with assessment of user needs and potential scientific impact, this then motivates the near- and long-term investments required to serve

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users and maintain leadership in x-ray science as described in each section and further detailed as a prioritized list in Appendix 1. The ultimate goal of this activity is to create a blueprint for state-of-the-art beamlines and ancillary experimental facilities that will fully support the APS user community in its quest to explore the most important problems.

The APS Upgrade is also entering the next stages of defining the detailed early science opportunities and corresponding beamline technical requirements for the upgraded facility. This process includes a set of community workshops to be held in late May and early June 2015. Therefore, over the next six months, the APS will revisit the x-ray science plans and prioritizations discussed in this document to ensure continued alignment with the long-term scientific drivers and needs of the user community, as must ultimately be realized for an upgraded APS.

6.1 X-ray Science for Chemistry Chemical processes are central to many global energy challenges. Photosynthesis, arguably the most important chemical reaction on the planet, is the process whereby sunlight is used to create carbohydrates from CO2 and water, and thus fuel the world. The synthesis of ammonia from N2 and H2 enables industrial-scale production of fertilizers. The catalytic converter in automobiles uses basic redox reactions to reduce the amount of pollutants a vehicle produces by converting harmful fumes into cleaner gases.

Scientists strive to achieve a fundamental understanding of chemical transformations and energy flow in complex systems to continually make these processes more efficient and sustainable. At the APS, high-energy synchrotron x-rays provide the ability to characterize chemical processes in situ on time and length scales ranging from the atomic to the macroscopic. In concert with recent advances in theory and computation, this can improve understanding and eventually lead to the development of new chemical processes and architectures.

The APS provides state-of-the-art facilities that accelerate understanding of complex chemical phenomena (Figure 6.1.1). Correlating chemical structure and function is facilitated by a multimodal approach that combines scattering methods to define atomic positions, spectroscopic methods to identify chemical speciation, and imaging/tomographic modalities to link atomic structure and chemical properties at the nanoscale. The high x-ray energy of the APS is critical for observing processes in situ and in operando in electrochemical, catalytic, and high-pressure environments. The APS operates a suite of beamlines located between sectors 9 and 12 that support high-energy scattering (>50 keV), simultaneous SAXS/WAXS, and x-ray spectroscopy primarily focused on chemical science. These beamlines feature the ability to measure spatial resolution that spans distances from directly bonded atom pairs to the mesoscale, and include high-throughput capabilities for rapid screening, standardized reaction vessels for catalysis, infrastructure for flow and characterization of reactive gases, and in some cases, a co-located infrared spectrometer. For the investigation of fundamental energy and charge transfer processes, the ability of an ultrafast excitation to coherently prepare an ensemble of molecules allows one to use x-ray pulses to investigate dynamics of molecular systems with atomic-level structural precision using pump/probe or pump/probe-probe-probe techniques. The 80% availability of the 24-bunch timing pattern at the APS enables this area of research and has attracted a substantial community to locate and invest at the APS.

Looking toward the future, the 100-fold increase in coherent flux provided by a MBA lattice will enable a corresponding increase in the intensity of nanofocused x-ray beams and the ability to study nanometer-size

Figure 6.1.1. Length- and timescales associated with chemical processes in complex heterogeneous environments.

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voxels with chemical specificity in complex chemical environments. The MBA upgrade will provide sufficient high-energy brightness to probe catalyst particles as small as 10 atoms. Hence, the APS Upgrade will enable new opportunities to spatially resolve the foundations for chemistry within complex materials and devices.

Thrust 1: Energy Storage The development of new technologies for electrical energy storage is critical to our national energy infrastructure and will impact a multitude of areas, including grid-based applications, electric vehicles for transportation, and personal electronic devices. The function of electrical energy storage devices is governed by phenomena that span multiple length and time scales. Incisive characterization tools are essential to advance our fundamental understanding of these phenomena and how they impact performance. Knowledge gaps exist in our understanding of charge transfer, mass transport, and structural changes. These gaps impede the rational optimization of capacity, charge rate, lifetime, and product safety.

Advanced Photon Source x-rays are utilized to penetrate complex multicomponent device architectures to resolve their function in both time and space, and develop fast time-resolved measurements that match the timescales of processes relevant to chemical energy storage, including charge transfer (femtosecond-picosecond), ions hopping on and off surfaces (picosecond), diffusion (millisecond), structural transitions and grain fracturing (seconds-minutes), and cell failure (hours-years). Observational challenges include understanding the behavior of the working ion (Li, Mg) in its surrounding nanometer sphere in the anode, cathode, electrolyte, and the solid-electrolyte interphase under working conditions.

The APS has a powerful suite of x-ray beamlines (PDF, absorption, emission, and Raman spectroscopy, high-energy tomography, spectromicroscopy, and coherent scattering) that yield insights into complex structures with atomic resolution. The APS provides the high-energy x-rays needed to penetrate an operating electrochemical environment and minimize radiation damage during the measurement process. An example of the benefit of this penetration power is the time-resolved, high-energy x-ray diffraction methods that were used to demonstrate that in the rapid-charge Li battery, the phase transformation of the nanoparticle electrode LiFePO4 to FePO4 proceeds via the formation of a metastable solid solution rather than via a classical nucleation and growth process [Liu et al., Science 344, 1252817 (2014).] For the multivalent Mg-ion battery, high-energy x-ray scattering combined with molecular dynamics simulation demonstrated that the Mg-ion solvation shell contained a counter-ion and hence is expected to have reduced mobility (Figure 6.1.2).

Research will benefit from plans to augment high-energy capabilities by installing a superconducting undulator to enhance the flux 5-fold and to add additional in situ Raman characterization capabilities. The enhanced dynamic two-dimensional (2-D) and three-dimensional (3-D) imaging capabilities will better characterize the electrode structures in operando.

Collaborators: The Joint Center for Energy Storage Research, the Center for Electrical Energy Science, the Northeastern Center for Chemical Energy Storage, and General Electric.

Figure 6.1.2. A schematic of a battery; the working ion is shown in the various environments that it encounters as it is shuttled from anode (right) to cathode (left). X-rays penetrate the electrochemical environment and provide structural and chemical information on the electrodes and the working ion during charge and discharge cycles.

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Thrust 2: Catalysis Chemical catalysis will be an important component of the quest for carbon-free energy. Catalysts are central to 90% of chemical manufacturing in our nation and play a role in the more efficient production of low/non-carbon fuels (e.g., hydrogen production via water-splitting); more efficient fuel and electrolytic cells; more effective catalytic converters; more efficient conversion of renewable resources (e.g., biomass) to fuels; and technologies for the sequestration, utilization, and/or permanent disposal of CO2.

To optimize the use of catalysts for sustainable energy, two main challenges must be overcome. First, the mechanisms and dynamics of catalytic transformations must be understood. Second, the synthesis of catalytic structures must be designed and controlled (Figure 6.1.3). The past decade has seen substantial advances in the ability of theory, particularly density functional theory, to predict the activity of designer catalytic structures. However, experimental studies under realistic conditions are always central to creating practical catalysts [Norskov et al., Nat. Chem. 1, 37 (2009)].

X-ray methods are poised to uniquely probe catalytic systems in situ, providing validation for the computational predictions for new catalytic compounds and solutions to practical problems with existing catalysts. Efficient catalysts are nanoscale and are rendered ineffective by sintering (agglomeration) under experimental conditions, which can be harsh (e.g., 10 atm, >700°). Small-angle x-ray scattering is optimally suited to detect changes in the size and shape of the catalytic nanoparticle or the nanopore in a surrounding capsule, while x-ray spectroscopy yields information on chemical state and nearest-neighbor identities and distances. Combining these techniques with the nanofocusing available from the proposed APS Upgrade will enable a transition from probing large ensemble averages to probing single particles.

Research in catalysis will also benefit from planned investments at the APS in quick extended x-ray absorption fine structure (QXAFS) spectroscopy, increased flux on the SAXS/WAXS beamline to enable time-resolved studies, an extended energy range on the powder diffraction beamline, enhanced flux on the high-energy scattering beamlines, and addition of an in situ Raman spectrometer.

Collaborators: Major partners in catalysis research include ExxonMobil Corporation, General Electric, Schlumberger, Chevron, Shell, Honeywell UOP, British Petroleum, General Motors, Johnson Matthey, Energy Frontier Research Centers, and many universities.

Thrust 3: Chemistry in Ordered Systems Understanding the development of structure during synthesis, and the synergy between structural and functional properties is critical for developing new chemical systems for industrially important applications. In situ x-ray scattering studies offer a powerful approach to achieve this understanding by revealing changes in structure and properties under conditions that mimic real-world applications. Focused and efficient expansion of the library of functional inorganic compounds will accelerate discovery of novel materials [Shoemaker et al., Proc. Natl. Acad. Sci. USA 111 (30) 10922 (2014)]. In situ techniques provide rapid diffraction signatures of all crystalline phases formed during processing. Rapid exploration of reactant phase space with high-throughput techniques is envisioned as a future specialty at the APS.

Figure 6.1.3. Catalytic particles on a surface display a variety of active sites. Synchrotron x-rays play a valuable role by characterizing catalytic action in situ. Nanofocusing in an upgraded APS, combined with spectroscopic imaging, will enable characterization of individual catalytic particles and their active sites under reactive conditions.

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Examples of chemical functionality induced within spatially organized systems include metal organic frameworks (MOFs). These porous materials, where the porosity and chemical affinity can be controlled by design, can have application for CO2 sequestration, gas storage and separation, drug delivery, molecular magnetism, and spin-state switching (Figure 6.1.4). For example, the structural changes that occur during the processes of activation by heating and subsequent CO2 loading can be followed by in situ powder diffraction.

Potential functional systems include nanoparticle superlattices by design. At the APS, the evolution of sophisticated 3-D structures synthesized with atomic-level precision using DNA linkers can be studied (Figure 6.1.5) [Macfarlane et al., Science 334, 204 (2011)]. Novel multicomponent structures may give rise to unique plasmonic, magnetic, or catalytic properties. Small-angle x-ray scattering provides an in situ view of the synthetic process and has recently enabled the formation of a ternary nanoparticle superlattice [Macfarlane et al., Science 341, 1222 (2013)].

Research in functional systems will benefit from the increased flux on the SAXS/WAXS beamline to enable time-resolved studies, the extended energy range on the powder diffraction beamline, the enhanced flux on the high-energy scattering beamlines, and the in situ Raman spectrometer.

Collaborators: Major partners in research into functional systems include Northwestern University, the University of Illinois at Urbana-Champaign, and many other universities.

Thrust 4: Fundamentals of Energy Transfer and Conversion Understanding the fundamentals of energy transfer and conversion is central to designing improved artificial photosynthetic systems. More generally, the investigation of light-activated chemical systems provides opportunities to resolve the fundamentals of chemistry, for example, allowing complex multi-electron bond-breaking, bond-making chemical transformations to be studied one electron at a time and with ultrafast time resolution. Unraveling the intricacies of light harvesting, charge separation, and photocatalysis is accomplished by mapping light-generated excited-state structural dynamics and their decay into product states Laser-synchronized, pulsed x-ray sources provide a means to map charge, energy, and structural reorganization in complex systems.

For the investigation of elementary-energy and charge-transfer processes, the ability of an ultrafast excitation to coherently prepare an ensemble of molecules allows one to use x-ray pulses to investigate the controlled dynamics of individual quantum systems with atomic-level structural precision on relevant time scales. Newly commissioned high-repetition rate, ultrafast lasers are accelerating research in this area.

Figure 6.1.4. CO2 capture in a nanoporous 3-D MOF with one-dimensional pores. Characterization of MOF pore structures during reactive gas loading is enabled by powder diffraction and small-molecule crystallography. Wriedt et al., Angew. Chem. 51, 9804 (2012)

Figure 6.1.5. Small-angle scattering probes of nanoparticle superlattice formation in situ providing real-time feedback as these materials are synthesized. The figure shows the first demonstration of a three-component nanoparticle lattice via DNA-mediated synthesis. Macfarlane et al., Science 341, 1222 (2013)

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The APS offers the ability to utilize the entire x-ray flux of the beam in a pump-probe or pump-probe-probe-probe fashion. This allows one to characterize transient species with fidelity comparable to that of the ground state. Previously, reliable x-ray spectroscopy measurements were mostly made on ground-state properties of bulk photoactive molecules. Now, measurements can be made of transient excited states using small volumes of dilute samples—a prerequisite for understanding small-quantities of discovery materials (Figure 6.1.6).

Research in this area will benefit from the extended energy range on the laser pump/x-ray probe beamline, the extension of high-repetition-rate excitation capabilities to other beamlines (via portable laser systems), the development of waveform-controlled pump pulses across multiple wavelength regimes (THz to UV), and development of efficient x-ray emission spectrometers. The proposed upgraded APS allows for the focusing of x-ray pulses to tens of nanometers and the observation of photo-induced chemical reactions on individual nanoparticles.

Collaborators: Major partners in this research include the Argonne-Northwestern Solar Energy Research Center and Argonne researchers in chemical sciences, numerous university research partners, geosciences and biological sciences.

Leading or unique capabilities: • A dedicated high-resolution PDF beamline: PDF is a versatile high-energy x-ray method (>50 keV)

applicable to a wide range of materials under a broad range of experimental conditions. It provides atomic-scale structural insights with crystallographic resolution, which is especially important for the study of emerging complex functional materials with atomic order limited to the nanoscale, an area where crystallographic methods fail.

• A high-throughput, high-resolution powder diffraction beamline: This beamline features a mail-in program, robotic sample changer, and varied sample environments (cryostream, cryostat, hot air blower). This bending-magnet powder diffraction beamline is one of the most productive in the world.

• High-throughput, simultaneous SAXS/WAXS beamlines: These beamlines feature a wide q-range (0.001-4Å-1) with rapid interchange of targets and sample environments. Unique simultaneous GISAXS/GIWAXS and USAXS/SAXS/WAXS capabilities (0.00003 - 5Å-1) enable users to sample an extended range of scattering vectors.

• A unique suite of laser pump/x-ray probe spectroscopy and scattering beamlines to study the dynamics of energy transfer and conversion processes: Beamline 14-ID, which has the world’s current highest-per-pulse flux at a synchrotron (4x1010 x-rays/pulse) for single-shot diffraction and scattering at repetition rates up to 1 kHz; beamline 11-ID-D, a laser-initiated, time-resolved spectroscopy and scattering beamline with repetition rates up to 10 kHz; and the 7-ID high-repetition-rate laser pump/x-ray probe with repetition rates up to 6.5 MHz.

Collaborators: DOE-BES Chemical Sciences and the National Institutes of Health (NIH).

• A transmission x-ray microscope (TXM, 40-nm spatial resolution): This newly developed TXM is suitable for dynamic studies at 1 sec/frame, is optimized for in situ studies with chemical specificity, and is fully integrated with micro-CT for zoom-in tomography.

• A high-speed, full-field imaging beamline: This unique beamline provides single-pulse imaging at 80-ps exposure time, with frame rates up to 6.5 MHz for four frames, and 271-kHz continuous movie mode with 1-µm spatial resolution.

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Near-term investments: APS-operated beamlines

• Extend the energy range on powder diffraction beamline 17-BM: Higher-energy x-rays (30 keV) will provide increased penetration power, decreased radiation damage, and increased signal-to-noise for many in situ studies.

Collaborators: Brookhaven National Laboratory, Argonne National Laboratory

• Install a quick-extended x-ray absorption fine structure (QXAFS) capability at beamline 9-BM: QXAFS will provide quick scanning capabilities to follow chemical reactions in real time and allow access to the important phosphorous and sulfur K-edges (2.1 to 21 keV).

Collaborator: ExxonMobil Corporation

• Increase the energy bandwidth on SAXS/WAXS beamline 12-ID: The increased flux (~100x) with a multilayer monochromator enables time-resolved studies on the nanosecond timescale.

Collaborator: Los Alamos National Laboratory

• Extend the energy range on laser pump/x-ray probe beamline 7-ID: The extended energy range (from the present lower limit of ~6 keV) enables access to important elements for energy transfer and conversion studies.

Collaborators: BES Chemical Sciences, Geoscience, and Biosciences research programs

• Install a single-line undulator (~23-keV, 1.8-cm period) on high-speed full-field imaging beamline 32-ID: This enables higher x-ray energy, reduces heat load on the sample and detector, improves flux at the detector 10-fold, improves signal-to-noise, and improves access to high-Z materials. These improvements will allow multimodal characterization with simultaneous imaging and diffraction with the use of two tandem undulators.

• Enable in situ Raman spectroscopy: Incorporate a distributed optical Raman spectrometer using optical fiber to sectors 9 through 12 for complementary in situ characterization capabilities, and enable portability to allow UV Raman capability at selected beamlines.

CAT-operated beamlines

• Improve SAXS/WAX and extended x-ray absorption fine structure (EXAFS) capabilities: The DuPont-Northwestern-Dow (DND) CAT at Sector 5 plans to continue to invest heavily in the SAXS/medium-angle x-ray scattering/WAXS capabilities on its insertion device beamline and the x-ray absorption near-edge structure (XANES)/EXAFS capabilities on its bending magnet beamline. During the next few years, DND-CAT will implement software and hardware to make the best use of the exciting features of recently purchased cameras.

Long-term investments: APS-operated beamlines

• Implement canted undulators at beamline 11-ID: This cant will provide complete independence for (currently) three simultaneously operating stations (two dedicated-PDF beamlines at ~60 keV and 110 keV, and one laser-pump/x-ray probe beamline). The present optical arrangement compromises the intensity stability of the PDF beamlines. This cant does not increase the total number of APS beamlines.

• Install superconducting undulator on 11-ID: This will provide ~5-fold increased flux at high x-ray energy for PDF studies to enhance throughput and time-resolved studies.

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• Develop stereo imaging beamline: This will enable 3-D information on ~millisecond time scales without sample rotation as typically required for synchrotron x-ray tomography. Implementation is carried out via canted undulators at 1 mrad, with >10-degree incident beams on sample. This is useful for studies of structural transitions, fluid dynamics, and transport through porous media.

CAT-operated beamlines

• Preparation to optimize improved x-ray beam: ChemMatCARS at Sector 15 has an advanced crystallography program that will benefit from the higher brightness beam from a MBA lattice, while the liquid surface/interface program will benefit from the proposed APS Upgrade’s enhanced coherence properties. Both programs will also see a significant increase in the intensity of high-energy x-rays. To take full advantage of these upgraded properties, ChemMatCARS needs a new mirror system, re-polished crystals on the monochromator, and mechanical system upgrades.

• Add new and expanded techniques: DND-CAT plans to use sub-micron, low-divergence beams and microfluidic technology to study individual nanoparticle assemblies with the new source characteristics of the proposed MBA lattice. As optics technology improves to preserve brightness in the vertical and horizontal planes, DND-CAT envisions being able to use focused beams for studies with x-ray standing waves. This opens new scientific opportunities to study much smaller areas (on the order of 100-square microns) of materials of technological importance. The MBA lattice may also enhance the flux available on beamline 5-BM, so DND-CAT plans to invest in the next generation of fluorescence detectors as they become available, especially in emergent high-energy sensitive (20-keV and up) silicon, germanium, and other semiconductor-type drift detectors.

DND-CAT is considering exploiting the greatly increased coherence of the MBA lattice (up to 10% of the beam at 10 keV) by capitalizing on phase contrast imaging made possible with the highly coherent source. It plans to explore the possibility of doing sub-micron-resolution tomography of low-absorption-contrast samples. The new coherent beam would allow for simpler implementation of multiple-detector distance, phase contrast propagation-based holotomography.

6.2 X-ray Science for Materials Synthesizing, understanding, and controlling the properties of advanced materials lie at the very heart of modern technologies. The increasingly rapid development of novel materials has been driven by improved synergies between synthesis techniques, theory, and characterization, with the information from each feeding back to the others. Synchrotron radiation plays a key role in this cycle by providing unique characterization tools for probing the structure, topology, electronic configuration, and dynamics of such systems under real operational conditions (Figure 6.2.1). Synchrotron-based techniques provide information across a wide range of length scales from inter-atomic to several millimeters, and time scales from sub-nanosecond to hours. This enables the direct coupling of the relevant time and length scales to a particular material’s functionality.

The APS provides state-of-the-art facilities that accelerate this materials discovery process and the exploration of the complex interactions at the core of modern functional systems. Today, the APS operates a suite of beamlines that encompass the breadth of current x-ray scattering, spectroscopic, and imaging techniques. The new instrumentation for probing materials developed at the APS leverages one or more of the unique core strengths of the facility, particularly the deep penetration of high-energy x-rays. This provides true bulk measurements and capabilities for observing materials in in situ environments relevant to

Figure 6.2.1. Rapid development of new advanced materials is driven by x-ray characterization coupled with materials modeling. Courtesy of Robert Suter, Carnegie Mellon University

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actual operating conditions and at the extremes of pressure, temperature, and field. The high brightness of the APS x-ray beam enables spatial-resolution imaging on the order of nanometers of the structure and elemental composition of designer advanced materials that are extrinsically or intrinsically heterogeneous on nanometer length scales. The high-intensity pulsed x-ray beam provides an excellent probe for understanding the dynamics of matter at time scales down to 100 ps.

The proposed upgrade of the APS storage ring will provide transformative capabilities for nanoprobe imaging and coherence-based techniques, such as x-ray photon correlation spectroscopy and coherent diffractive imaging (CDI) that probe materials with even greater fidelity.

Thrust 1: Engineering Materials The past 15 years have seen remarkable advances in producing engineering materials that are more efficient, safer, and durable than previously available. For example, the most modern generation of airplanes built today contain 20-50% composite materials in their primary structures. The development of newer materials with further functional improvements, however, rests on obtaining experimental data across a wide range of length scales that will help validate computational models that link performance to materials processing, microstructure, and properties.

The APS has several unique structural characterization tools for probing functional engineering materials, such as high-energy diffraction microscopy (HEDM), micro-Laue, and dynamic phase-contrast tomography. The datasets that these techniques provide are increasingly being used to stringently test and refine micromechanical models and impact programs such as the Materials Genome Initiative. These capabilities have attracted sophisticated sample environments from partners, such as a worldwide-unique, high-precision, in-grip rotation apparatus for in situ mechanical loading (Air Force Research Lab) and a vacuum furnace for in situ thermo-mechanical loading of irradiated materials (Figure 6.2.2).

To further enhance these high-energy capabilities, a new 1.0m-long superconducting undulator will be installed on beamline 1-ID to provide nearly 5-fold flux increase for energies above 50 keV. The spatial resolution and stability of HEDM on 1-ID will be pushed to 1 µm from the current 5 µm, enabling mapping of the microstructure and strain of intrinsically heterogeneous systems. Integrated approaches toward data handling and processing using high-performance computing will be developed to handle the large volume of data generated by these techniques (~10 TB/day). Further out, the high brightness at high energies of the MBA lattice will extend HEDM and scattering tomography techniques to increasingly complex materials, with improved resolution.

Research on engineering materials will directly benefit from the installation of new superconducting undulators on beamlines 1-ID and 6-ID-D, and from an additional branch line on 1-ID. Together, these double the capacity for this technique, which is in extremely high demand. The dynamic tomography beamline with micron-scale resolution and millisecond acquisition times will also be a key for this field.

Collaborators: Major partners in engineering materials research include the Air Force Research Lab, Argonne Nuclear Engineering, Lawrence Livermore National Laboratory, Los Alamos National Laboratory, several universities, and industrial partners such as General Electric and Caterpillar.

Figure 6.2.2. An innovative load frame with custom built furnace mimics the in operando thermo-mechanical stress conditions in turbine engines. HEDM measurements provide information for improving the thermo-barrier coatings on the turbine engine blades. Knipe et al., Nat. Comm. 5, 4559 (2014)

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Thrust 2: Emergent Materials Emergent materials, often based on quantum phenomena, have complex underlying interactions with similar energy scales that compete and couple with one another to yield exotic new phenomena. Users of the APS exploit the high brightness, penetration power, and time structure of APS x-ray beams to probe charge, spin, orbital, and structural order in such systems. In some cases, these studies occur under extreme conditions of pressure, magnetic and electric fields, and low temperature. Fast-polarization modulated spectroscopy provides insight into emergent electronic and structural phenomena in systems with reduced dimensionality. The time structure of APS beams is utilized to probe (~100-ps) magnetization dynamics in artificial nanostructures for applications in magnetic recording and spintronic devices.

A number of APS beamlines focus on studies of quantum materials utilizing polarization-dependent spectroscopy, resonant x-ray scattering and imaging, high-energy-resolution inelastic scattering (HERIX), and resonant inelastic x-ray scattering (RIXS) (Figure 6.2.3). A new intermediate-energy beamline (250-2,000 eV) that supports resonant soft x-ray scattering (RSXS) and angle-resolved photoemission (ARPES) is being added to the arsenal of tools. This beamline (IEX), was jointly developed by DOE and the NSF through a partnership between the APS, the University of Illinois at Chicago, the University of Michigan, and the University of Illinois at Urbana-Champaign. Additional x-ray photoemission capabilities are also being added at the Materials Research (MR) CAT 10-ID beamline.

The APS is collaborating with the Argonne Materials Science Division to develop new capabilities for in situ growth studies of materials phenomena, particularly synthesis that cannot be done in UHV and which cannot be studied using electron diffraction and spectroscopy techniques. A new oxide molecular beam epitaxy (MBE) chamber recently installed at beamline 33-ID is unique worldwide at a synchrotron, and provides a novel platform for studying the growth of complex oxide heterostructures. Similarly, a highly flexible diffractometer with provisions to accommodate a wide variety of synthesis and processing chambers is currently being deployed at beamline 12-ID-D.

A unique high-field terahertz pump coupled with a nanoscale diffraction apparatus will be used for studies of field-driven phenomena on ultrafast time scales relevant to information processing. These new capabilities couple with strong research programs in correlated quantum systems at Argonne and numerous academic institutions.

Research in emergent materials benefits directly from the new IEX beamline and its ARPES and RSXS end stations, the new beamline for RIXS, the doubled capacity of the HERIX beamline, the new MBE-oxide chamber, and expanded pump-probe nanodiffraction capabilities.

Collaborators: Major partners in research into emergent materials research include the University of Illinois at Urbana-Champaign, the University of Illinois at Chicago, The University of Chicago, the University of Michigan, and the Argonne Materials Science Division.

Thrust 3: Extreme Conditions The search for and discovery of new phases of matter at the extremes of pressure, temperature, and electromagnetic fields provides a route to advancing our understanding of a large array of fundamental problems in condensed matter physics, geophysics, and materials synthesis. The most extreme conditions

Figure 6.2.3. RIXS has been recently used to observe magnetic excitations in a strongly spin-orbit coupled 5d transition-metal oxide. Kim et al., Phys, Rev. Lett. 108, 177003 (2012)

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are typically realized across small, encapsulated volumes, so the high-brightness, penetrating, micron-sized APS x-ray beams are ideally suited for these studies, which include radioactive or irradiated materials and systems under large shock compression.

Users of the APS have long been leaders in studying materials properties at high pressure in diamond anvil cells (Figure 6.2.4). Specifically, the High Pressure (HP) CAT is fully dedicated to such studies, while the GeoSoilEnviroCARS CAT (GSECARS-CAT) facility provides around 50% of its beam time to these measurements. In addition, the APS is the home of HPSynC, a center run by the Geophysical Laboratory at the Carnegie Institution of Washington that promotes high-pressure research across the facility. In addition, a number of other beamlines with unique measurement capabilities offer high-pressure and other extreme environments.

The APS will pursue a coordinated approach to developing instrumentation that expands the range of extreme conditions accessible using these x-ray techniques. New instruments will provide simultaneous high-pressure, high- and low-temperature, and magnetic field capabilities for x-ray magnetic circular dichroism (beamline 4-ID-D), resonant x-ray scattering (6-ID, 27-ID), and coherent diffraction (34-ID). Pulsed magnets that can provide much higher magnetic fields are being developed in a partnership with the National High Magnetic Field Lab (NHMFL) at Los Alamos National Laboratory to explore the magneto-structural behavior of matter. A new scheme that utilizes a fast x-ray chopper will be applied to greatly speed up synchrotron Mössbauer measurements (3-ID) to probe dynamic properties (e.g., sound velocities) at high pressure. In the long term, the nanoscale beams delivered by the proposed MBA lattice enable experiments at even higher pressures and magnetic fields, as well as provide dramatic new capabilities for exploring heterogeneity across materials at extreme pressures using nanoscale scanning spectromicroscopy and coherent scattering methods. The extreme-conditions research community will benefit from continued improvements in instrumentation that expand the accessible pressure, temperature, and field phase space, such as the addition of a chopper for the nuclear resonant scattering beamline, the superconducting undulator upgrade to beamline 6-ID-D, and optics upgrades to the polarization-controlled beamlines.

Collaborators: Major partners in research into extreme conditions include the partner CATs at the APS (HP and GSECARS), HPSynC, the Consortium for Materials Properties Research in Earth Sciences, the NHMFL, and the Argonne Materials Science Division.

Thrust 4: Soft Matter Soft materials play an important role in applications such as food, solar cells, consumer products, and templates for nanolithography for next-generation microelectronics. The function and performance of soft materials is highly correlated to a hierarchy of structural length scales, including atomic, mesoscale, and macroscopic, as well as time scales from milliseconds to hours. The APS offers users several tools, such as SAXS (beamlines 5-ID and 12-ID), grazing-incidence x-ray scattering (GIXS, at 8-ID-E and 12-ID, Figure 6.2.5) and x-ray photon correlation spectroscopy (XPCS, at 8-ID-I) that access all of these temporal and spatial scales, providing a full picture of how soft matter assembles and responds dynamically.

Figure 6.2.4. Coherent scattering has recently been used to obtain 30-nm-resolution strain maps in gold nano-crystals as a function of applied pressure. Wang et al., Nat. Comm. 4, 1680 (2013)

Figure 6.2.5. GIXS can be used to improve the process for making photovoltaic cells composed of microphase-separated conjugated block copolymers. Guo et al., Nano Lett. 13, 2957 (2013)

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Further advances in understanding self-assembly and particle synthesis require instruments with improved temporal and q-resolution, and chemical sensitivity. New focusing schemes with simultaneous SAXS/WAXS will be developed on beamline 12-ID to provide this improved resolution, while resonant soft x-ray scattering measurements on the IEX beamline will provide chemical sensitivity for soft-matter, long-period structures. Recent advances in XPCS capabilities at the APS have been provided by the addition of a second undulator for beamline 8-ID and the deployment of a fast, charge-coupled device (CCD) detector developed in a partnership between Argonne and Lawrence Berkeley National Laboratory. The combination of these improvements has extended the dynamic range of XPCS by nearly two decades in time sensitivity.

Looking ahead, the greatly increased coherence at higher energies delivered by the proposed MBA lattice will provide a 4- to-6-order-of-magnitude increase in the time sensitivity for XPCS, revolutionizing the ability to probe the dynamics of systems in attenuating sample environments, such as electrochemical cells with applications to energy storage.

The soft-matter research community stands to benefit from enhancements for faster XPCS, better q-resolution, faster GIXS/SAXS/WAXS, and new capabilities for resonant soft x-ray scattering.

Collaborators: Major partners in soft-matter research include The University of Chicago, McGill University, and other universities; Lawrence Berkeley National Laboratory; and the Argonne Materials Science Division.

Thrust 5: Materials Far From Equilibrium Many phenomena occur in systems that are far away from equilibrium. Understanding how such systems evolve, and learning how to control their behavior, could yield dramatic improvements for technologies as varied as energy storage and electronics. APS users exploit the high-repetition-rate train of high-flux x-ray pulses to study matter far from equilibrium using various methods to create a novel state (optical lasers, high-velocity gas guns, pulsed magnetic fields, etc.) in a pump-probe-probe-probe configuration, or simply to watch complex systems spontaneously evolve in a probe-probe-probe manner. This cross-disciplinary theme was one of the original 2008 BES Grand Challenges, and it was noted that x-rays would play a critical role in bridging understanding from the quantum to the macroscale in diverse fields such as fluid dynamics, shock physics (Figure 6.2.6), combustion, dynamic self-assembly, spontaneous organization, and defect formation.

Beamlines at the APS associated with this type of dynamics research are the new Dynamic Compression Sector for shock physics at Sector 35 (recently constructed in partnership with Washington State University and funded by the National Nuclear Security Administration); the ultrafast full-field imaging beamline (32-ID), where both the megahertz-frame-rate detection schemes and x-ray imaging of fuel sprays were initially developed and demonstrated; the BioCARS (Sector 14) beamline; and the x-ray photon correlation spectroscopy beamline (8-ID-I), where intensity fluctuations of the coherent speckle pattern reflect the dynamics of the sample.

Upgrades to the ultrafast full-field imaging 32-ID beamline will incorporate stereo imaging using canted undulators to form two sources and create a 3-D ultrafast imaging camera. This area of research directly benefits from development efforts in fast-frame-rate x-ray detectors and scintillators.

Collaborators: Washington State University, Los Alamos National Laboratory, Lawrence Livermore

Figure 6.2.6. A schematic view of an ideal crystal undergoing elastic and plastic deformation, followed by a phase transformation during shock compression. Courtesy of Hector Lorenzana, Lawrence Livermore National Laboratory

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National Laboratory, BioCARS, and the Argonne Chemical Sciences and Engineering Division.

Leading or unique capabilities: • The high-energy scattering beamline for characterizing the microstructure, stress, and strain of

inherently heterogeneous engineering materials under realistic thermo-mechanical loading conditions: This is accomplished by a unique combination of simultaneous HEDM, tomography, and SAXS/WAXS that provides information across atomic, mesoscopic, and macroscopic length scales.

• High-pressure research using x-rays: Two APS sectors are dedicated to high-pressure studies: HP-CAT and GSECARS-CAT. These provide a range of measurement capabilities and ancillary labs for high-pressure studies. The HPSynC consortium at the APS serves as the national center for high-pressure research and provides additional capabilities at other APS beamlines.

Collaborators: The University of Chicago, the Carnegie Institute of Washington

• Dynamic compression beamline: Currently in the commissioning phase, this beamline, which is unique at a synchrotron source, transitions to operations in 2015 to provide insights into the real-time, atomistic-level responses of materials under extreme dynamic loading conditions using x-ray imaging and diffraction.

Collaborator: NNSA

• Intermediate energy x-ray beamline: This beamline has an innovative, variable polarization, quasi-periodic undulator for RSXS and ARPES measurements that probe the long-range order and energetics of electronics states in quantum materials.

Collaborators: DOE, the NSF, the University of Illinois at Chicago, the University of Illinois at Urbana-Champaign, and the University of Michigan.

• Resonant inelastic x-ray scattering beamline: This beamline enables probing of the electronic and magnetic excitations of materials under applied pressure and low temperatures.

• Terahertz-radiation pump/x-ray probe instrumentation: This capability, combined with nano-focusing, enables selective excitation of particular quasiparticles for studies of dynamics in complex materials with multiple competing interactions.

• Rapid polarization-modulated spectroscopy (1-10 Hz): This enables investigations of the magnetism of small-moment and dilute systems at the extremes of temperature, magnetic field, and pressure.

• Synchrotron Mössbauer spectroscopy with simultaneous high pressure and high temperature, as well as high magnetic field and low temperature: This is utilized for probing isotope-selective lattice dynamics and magnetism.

• Dynamic tomography measurement capabilities (10-100 Hz): This allows examination of the 3-D response of materials under a variety of external stimuli.

Near-term investments: APS-operated beamlines:

• Install a new, 1-m-long superconducting undulator on beamline 1-ID: This provides an additional 5-fold increase in flux above 50 keV. Combined with improved optics, it enhances the spatial resolution and stability of high-energy diffraction microscopy measurements to 1 µm from the current 5 µm, enabling mapping of the microstructure and strain of intrinsically heterogeneous systems.

• Upgrade the prototype superconducting undulator (SCU0) on beamline 6-ID-D with a longer

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magnetic array and optimized period: This provides a 4-fold increase in high-energy flux, increasing throughput and improving time-resolved structural studies.

• Extend Mössbauer spectroscopy capabilities on beamline 3-ID: This entails installation of a fast chopper system that speeds up the acquisition of time-domain spectra by 10-100x, opening new avenues for studying the local structure and magnetism of materials at extreme pressures.

• Refurbish optics and provide advanced detector systems for beamline 8-ID-I: This provides improved time-resolution for XPCS measurements and expand capabilities of this beamline in preparation for the proposed MBA upgrade.

Long-term investments: APS-operated beamlines: • Construct an additional branch line on beamline 1-ID: This doubles capacity and provides new

capabilities for high-energy structural characterization of advanced engineering materials, an area with significant over-subscription.

• Construct a new station at 34-ID to relocate the Bragg CDI program on 34-ID-C and nano-diffraction from 2-ID-D: A new, next-generation, high-stability diffractometer would provide enhanced capabilities for both these programs.

• Install new variable line-spacing optics on beamline 4-ID-C: This increases the available flux by a factor of 10-100, enabling a new class of studies on dilute magnetic systems.

• Replace optics on beamline 33-ID: This provides advanced surface characterization capabilities that optimally exploit the x-ray beam coherence for both ex situ (e.g., x-ray reflection interface microscopy) and in situ studies (e.g., oxide molecular beam epitaxy).

• Refurbish optics on beamline 6-ID-B: This provides focusing for resonant scattering studies of materials at extreme pressures and magnetic fields.

CAT-operated beamlines: • Extend high-pressure and time-resolved studies: HP-CAT at Sector 16 and GSECARS-CAT at

Sector 13 plan to develop improved focusing capabilities to access higher pressures (~TPa) in diamond anvil cells, and extend the reach of high-pressure tomography in multi-anvil presses and pink-beam micro-tomography for time-resolved studies of fluid flow. New types of diamond anvil cells are being developed that enable rapid pressure modulation to pursue dynamic pressure studies. Most high-pressure work is currently performed under static pressure conditions.

Collaborators: The University of Chicago, Carnegie Institute

• Add vacuum system and detectors: Materials Research CAT at Sector 10 adds high-energy x-ray photoemission (XPS) capabilities in fiscal year 2015. The XPS vacuum system and detectors will be installed in the beamline 10-ID experiment station, to be operational within a year.

Collaborator: Illinois Institute of Technology

• Install a high-power laser system: The Dynamic Compression Sector (35) starts initial user operations in 2015 with gas and powder guns for compression studies. Future plans call for the installation of a large, high-power laser system for photo-initiated shock studies.

Collaborator: NNSA

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• Construct a dedicated beamline for x-ray scanning tunneling microscopy (SX-STM) on Sector 26. The 26-BM port will be developed to accommodate the TXM and SX-STM instruments that share time with nanodiffraction on 26-ID. SX-STM provides unique capabilities for elemental, chemical, and spin-sensitive imaging measurements at or near atomic-scale resolution. A dedicated location for SX-STM enables development of more complex sample environments such as low-temperature. The 26-ID optics will be improved to ensure that the two-order increase in brightness provided by the proposed MBA upgrade will directly translate into a 100x greater nano-focused flux on a sample.

Collaborator: The Argonne Center for Nanoscale Materials

6.3 X-ray Science for Biological and Environmental Studies A Grand Challenge in life sciences is to understand the structure-function relationship, which connects the structure of proteins and other important molecules to their function within organisms through their role in organelles, cells, organs, and beyond (Figure 6.3.1). This relationship lies at the heart of key questions such as: How do integral membrane proteins perform their very diverse, biologically important functions? How do complex molecular machines perform their tasks? How do drugs interact with their targets? How do side effects arise, and how can drugs be improved? More generally, life scientists explore problems at both fundamental and applied levels, with a major focus on understanding, preventing, and curing disease.

The APS provides users with proven capabilities for addressing this relationship. For example, crystallography is essential for understanding the structure of the individual components and their complexes at the atomic level. SAXS/WAXS techniques reveal the behavior of proteins in conditions typical of in vivo systems: protein interactions and large scale effects of drug/ligand binding. X-ray fluorescence microscopy explores metalloprotein function, for example when the local chemical/trace metal environment varies. X-ray (micro)-diffraction plays an important role in studies of biomineralization.

The biological and environmental sciences communities at the APS are both large and vigorous, accounting for more than 42% of all APS users. Most research is conducted on CAT beamlines or beamlines operated jointly with the X-ray Science Division (XSD), such as the Bionanoprobe and the General Medical Sciences and Cancer Institute Structural Biology Facility (GM/CA-XSD).

Funding typically comes from sponsors such as the NIH or the DOE Biological and Environmental Research (BER) program that are distinct from the DOE-BES program. CAT capabilities are available for use by General Users at least 25% of the time. Although APS-operated beamlines may not have life sciences as their focus, biological research is performed on almost every beamline at the APS.

Near-term upgrades will add new capabilities such as in situ crystallography of microcrystals and enhance others such as the spatial resolution accessible in various imaging modalities. Long-term investments will be strategically directed to fully exploit the proposed upgrade of the APS storage ring through the MBA lattice. For example, the increased brightness allows large macromolecular complexes to be studied in more readily available, sub-micron crystals and improve the spatial resolution (10-50 nm) in imaging micro-probes.

Biological and environmental sciences work at both CAT- and APS-operated beamlines falls generally into

Figure 6.3.1. The Grand Challenge of understanding life is elucidating structure-functions relationships across the entire hierarchy from protein to organism.

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four thrust areas that encompass capabilities available today and that can be optimized within the next five years.

Thrust 1: Structural Biology Macromolecular crystallography is the most powerful tool for determining the structure of biological macromolecules with high biomedical importance at the atomic level (Figure 6.3.2), but requires that diffraction-quality crystals be obtained. For many Grand Challenge questions, crystals tend to be either small (micron size) or larger, structurally heterogeneous; both diffract weakly. Recent developments have shown that larger crystals, previously discarded due to poor diffraction, can yield excellent data when only a smaller and structurally homogeneous portion of the crystal is illuminated with a minibeam or a microbeam. Further, data may be collected from crystals that remain within their crystallization device and thus avoid the damaging stresses that occur during cryo-freezing or mounting. It is now even possible to collect data from tiny crystals that grow naturally inside cells — in cellulo. Smaller crystals allow photoelectron escape and are thus less prone to radiation damage. These approaches open access to previously inaccessible protein structures such as that of the human β2 adrenergic receptor, a G-coupled protein receptor whose structure determination was a major breakthrough (2012 Nobel Prize in Chemistry, based in large part on studies at the APS) for this important class of proteins and drug targets. Nanoliter crystallization technology, serial crystallography, and the use of synchrotron microbeams may revolutionize structural biology.

The current brightness of the APS and the large unit cell parameters of typical crystals limit the minimum useful x-ray beam size and therefore crystal size to approximately 5 µm or larger. This is a major bottleneck for structure determination of systems of particular interest to cell biologists, which often form even larger complexes involving many molecules. The proposed MBA lattice will provide a 100-fold increase in brightness and enhance beam stability, which allows routine structure determination from crystals as small as 0.5 µm. However, radiation damage limits the amount of data that can be collected from a single crystal, which requires that a complete dataset be assembled by merging partial data sets from multiple (>10) small crystals. Merging procedures will benefit from new tools being developed for serial crystallography at both free-electron laser and synchrotron sources. These advances allow the structures of even larger protein complexes to be determined routinely and become the next breakthrough area for the treatment of diseases. To meet these challenges, GM/CA-XSD (23-ID-D) and SBC-CAT (19-ID-D) plan to develop new end stations providing high-intensity, 1-µm-beam capabilities. All function involves changes in structure, which suggests that it is crucial to move beyond static structure to probe structural dynamics on all relevant time scales. Picosecond time-resolved Laue crystallography performed at BioCARS-CAT (14-ID-B) has resolved structural changes with 100-ps resolution (Figure 6.3.3). However, these dynamic studies are limited by the pump-probe

Figure 6.3.2. The ribbon representation of the β2 adrenergic receptor-Gs protein complex. This integral membrane receptor is shown in green with an agonist bound (yellow), and the trimeric Gs-protein components (Gα - orange, Gβ - cyan, and Gγ – purple). Courtesy of Brian Kobilka, Stanford University

Figure 6.3.3. Time-resolved structural changes recorded 100 ps after photoexcitation of the blue light PYP photoreceptor. The ground-state electron density map is colored magenta and the 100-ps map is colored green. The magenta-to-green color gradient unveils the direction of atomic motion. Courtesy of Philip Anfinrud, National Institute of Diabetes and Digestive and Kidney Diseases / National Institutes of Health

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method, whose time resolution is in turn limited by the convolution of the profiles in time of the pump (laser) and probe (x-ray) pulses. To address these limitations, the APS will develop a detector with high frame rate to enable pump-once, probe-many experiments. The increased brightness afforded by a MBA lattice will allow the study of microcrystals of larger protein complexes. More importantly, microcrystals are better stimulated by the pump laser beam, which both increases the time-dependent diffraction signal and decreases the background.

Collaborators: DOE-BER program, the NIH, pharmaceutical industry, universities

Thrust 2: Structure of Biomolecular Complexes in Solution to Near-Atomic Resolution Most important biological processes occur in solution, but crystal structures of macromolecules are important to provide guidance concerning what may occur under in vivo conditions. Solution x-ray scattering to study molecular structure and dynamics is thus a powerful complement to crystallography and solution nuclear magnetic resonance (NMR) spectroscopy, aided by the ease with which static and dynamic data can be collected on very large complexes under multiple physiologically relevant states. In the late 1990s, ab initio structural methods and computational programs emerged that allow the 3-D molecular envelope to be derived from SAXS data.

Conventional solution x-ray scattering is currently limited by its relatively low resolution that arises from free molecular tumbling and isotropic molecular orientation averaging. In order to improve the resolution, one- or two-

dimensional ordering of molecules will be induced through molecular alignment strategies such as surface alignment, flow alignment, and magnetic/electric field alignment (Figure 6.3.4).

Successful alignment will significantly increase the information content in the scattering patterns and enable us to study, at near-atomic resolution, large RNA molecules and protein complexes, which are typically difficult to crystallize. For example, surface-tethered rpRNAs are expected to align along the Z-axis while randomly oriented in the X-Y plane, and this anisotropic orientation can be measured using a GIXS technique (Figure 6.3.4). The 2-D GIXS data have higher information content and can provide a 3-D molecular envelope or molecular model with near-atomic resolution. The increased brightness of the proposed MBA lattice will dramatically enhance this method since the number of molecules illuminated by the x-ray beam will be reduced compared to traditional solution scattering from isotropically oriented molecules. These methods, instrumentation, and data analysis software have been developed at beamline 12-ID-B.

Collaborator: National Cancer Institute of the NIH

Thrust 3: Structure and Function – Organelles to Cells to Organisms Transition metals such as zinc, copper, and iron are essential trace nutrients for all forms of life. In humans, their dysregulation can lead to devastating diseases (e.g., Menke’s and Wilson’s diseases) and numerous neurodegenerative diseases are also believed to have trace-metal associations (e.g., Alzheimer’s). Metal

Figure 6.3.4. Simulated solution x-ray scattering (blue) and line cut profiles (in-plane, red; out-of-plane, green; diagonal, magenta) of 2-D GIXS pattern (inset) of rpRNA with uniaxial alignment. Courtesy of Xiaobing Zuo, Argonne National Laboratory

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homeostasis is also starting to be implicated in reproductive health. In general, transcription factors that regulate gene expression often contain a DNA-binding zinc-finger domain and therefore depend on the availability of zinc, as do many other regulatory proteins. Zinc is also paired with copper in the anti-oxidant protein copper/zinc superoxide dismutase, which has been implied in cellular aging. Its mutant forms have been linked to neurodegenerative diseases such as amytrophic lateral sclerosis.

Metals are also increasingly used in diagnostic or therapeutic agents for the study or treatment of diseases. Quantitative study of the redistribution of trace elements in response to challenges provides important information about functions and pathways of metalloproteins and allows the cellular targeting of therapeutic approaches to be studied. For example, Cisplatin, with platinum as its active ingredient, is a major chemotherapeutic drug, and numerous metal-based active agents are being actively researched as new drugs (e.g., ruthenium-based drugs). Magnetic resonance contrast-imaging agents are often metal-based. Some are in routine use (e.g., gadolinium-based agents) and others are in the R&D pipeline (e.g., Vanadyl-based compounds). X-ray fluorescence imaging can be used to understand and help model the behavior of novel imaging agents at the intracellular level. Similarly, novel nanocomposites combine therapy with diagnosis (“Theranostics”) and these are often metal-based.

Trace metals play a major role in plant systems that directly impact human health. Plants are the main food source for the majority of the world population, yet in some areas, staple foods lack the required trace metals. Deficiencies lead to numerous diseases and can further exacerbate the effects of toxic trace metal exposure. For example, selenium deficiency is believed to be an underlying factor in arsenicosis and cancer. Genetically engineering plants to increase nutrient uptake could, for example, ensure that pregnant women in underdeveloped countries get adequate amounts of iron. On the flip side, inhibiting the uptake of toxic metals by food plants could reduce toxicity and, thus, illness.

X-ray fluorescence microscopy offers a unique way to quantifiably image trace metals within whole cells and tissue sections (Figure 6.3.5) with sensitivity about 1,000x that of electron microprobe analysis. Characterization of precise metal concentrations, their spatial distribution, and chemical speciation in individual cells and cell compartments will provide much needed information to explore the metallome in health and disease, in both mammalian and plant systems. Although transmission electron microscopy offers unparalleled spatial resolution for structural studies of ~100-nm-thin sections and isolated macromolecules, x-ray nanoprobes are able to image whole cells and tissue sections up to many tens of micrometers thick and in three dimensions, thus placing trace metals firmly in their physiological context. The APS already plays a leading role in x-ray fluorescence microscopy studies of trace elements in biological systems. With the increased brightness offered by the proposed MBA lattice, improved efficiency of nanofocusing optics, and other advances described in the computation and instrumentation part of this facility plan, a roughly 1,000-fold increase in the focused flux is expected. This increase can be used for some combination of improved spatial resolution, trace element sensitivity, increased field of view, and/or

Figure 6.3.5. Transition metals such as zinc, copper, and iron are essential trace nutrients for all forms of life. Here the zebrafish was used as a model system to visualize tomographically the metalloprotein cofactor metal distributions correlated with characteristic anatomical features of embryonic development. [D. Bourassa et al, Metallomics 6(9), 1648 (2014)]. R&D activities in zone plate stacking directly translate to increased focused flux corresponding to improved spatial resolution in these systems. Improved approaches to tomographic reconstruction will enable data acquisition at increased speed maintaining full fidelity of the reconstruction. Hong et al., J. Synchrotron Rad. 21 (1), 229 (2014)

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improved statistics in quantitative studies involving multiple cells. As an example, the proposed APS Upgrade will enable the acquisition of a dataset such as the zebrafish embryo in Figure 6.3.5, to be imaged at 100-nm spatial resolution across the full 3-D field of view compared to the current 2-5 µm.

Thrust 4: Environmental Science and Geoscience Environmental and geoscience systems are inherently complex, heterogeneous, and multi-component. A Grand Challenge is to develop integrated characterization and modeling of such systems at multiple length scales, ranging from atomic (for example, arsenic chemical binding changes as revealed in x-ray spectroscopy and mineral phases as revealed by diffraction) to mesoscopic and macroscopic (for example, oil percolation through sandstones and shale). This knowledge can help optimize the cleanup of wastes from DOE nuclear legacy sites by exploring how subsurface bacteria change the chemistry of their environment and thus affect mineral speciation and precipitation. Understanding the spatial distribution of nuclear wastes is critical to developing effective plans for remediation of contaminated sites.

Spectroscopic methods provide atomic-scale understanding of bonding and valence even for very dilute components, while imaging and scattering techniques extend the characterization from the nanoscale to the bulk (centimeter) scale. A crucial strength of high-energy x-ray methods is the ability to study samples in situ and at extremes of temperature and pressure.

Environmental and geoscience research at the APS involves the use of both CAT-operated beamlines (Figure 6.3.6) and APS-operated beamlines. For example, the beamline 2-ID microprobe is used to map elemental distribution and chemical binding states in soils and bacteria; at 2-BM, x-ray tomography is used to study how minerals collect in pores to aid commercial mineral extraction. Beamlines 20-ID and 20-BM are operated in partnership with the Canadian Light Source and are very productive in microprobe spectroscopy, which supports multiple in situ studies, including high pressures, radioactive, and anaerobic samples.

The proposed MBA lattice will provide many opportunities for further improvements. Imaging and microprobes will directly benefit from the increased brightness: 10x better resolution or 100x flux for same spot size, thus yielding lower detection limits, faster scanning, and access to studies at more extreme conditions with smaller beams. For example, one could carry out the measurements shown in Figure 6.3.6 on individual bacteria instead of assemblages, and thus learn of variations within a bacterial strain. Leading or unique capabilities: APS-operated beamlines

• High-spatial resolution spectromicroscopy: This suite of APS instruments is unmatched globally in completeness of capabilities for studying biological and environmental samples with 30 to 200-nm resolution. These include: the Bionanoprobe, as noted above; beamline 2-ID-B, which provides soft x-rays (635-2,900 eV) to study resonances of low-Z elements (e.g., P and S K-edges); 2-ID-D, which provides microfluorescence, microdiffraction, and micro-XANES analysis; and 2-ID-E, which supports x-ray fluorescence imaging, tomography, spectroscopy, and microdiffraction.

Figure 6.3.6. Researchers from the Argonne Biosciences Division have recently used the APS to show that sulfur redox reactions can be the dominant energy source for Shewanella bacteria in deep, alkaline groundwater environments. These bacteria can enzymatically reduce elemental sulfur (S0) but not the iron in goethite, explaining why they maintain genetic pathways for both forms of respiration. Flynn et al., Science 344, 1039 (2014)

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• Solution x-ray scattering with near-atomic resolution: Beamline 12-ID-B provides solution bioSAXS and GIXS x-ray scattering capabilities. The grazing-incidence bioSAXS capability being developed will deliver near-atomic structural resolution without the need for crystals.

• Spectroscopic probes for biological and environmental samples: Beamline 20-ID-B,C has dedicated facilities for micro-XAFS, time-resolved XAFS, and x-ray powder diffraction (XRD), and an x-ray Raman spectrometer (LERIX) at the 2-µm level.

• X-ray reflection interface microscopy: This unique capability was developed by the Argonne Chemical Sciences and Engineering Division. This microscope (33-ID-D) uses a Fresnel zone plate for reflection imaging of mineral surfaces, with single atomic-step sensitivity and an ability to study chemical reactivity at hydrated mineral surfaces, providing insights into environmentally important processes and their effects on surface charge density.

• Cryogenic sample preparation laboratory: The APS is a leader in bringing cryogenic techniques to x-ray microscopy for the study of hydrated biological specimens with optimized structural and chemical preservation, as well as mitigation of radiation damage. The sample preparation laboratory has robotic-plunge freezing, high-pressure freezing, cryo-ultramicrotomy, and cryo-light microscopy capabilities as well as cell culture facilities.

Collaborators: Equipment is provided by the NIH and Argonne; operations funding comes from the NIH through Northwestern University.

CAT-operated beamlines

• World-leading productivity: The APS houses the largest concentration of macromolecular crystallography (MX) beamlines (~15 beamline equivalents). The beamlines are highly automated; most have high-performance detectors and many support remote-access data collection. More than 20% of all crystal structures deposited in the Protein Data Bank (PDB) result from data collected at APS beamlines; 19-ID-D is the most productive beamline worldwide with 3,262 PDB deposits. The impact is exemplified by the 2009 and 2012 Nobel Prizes in Chemistry, awarded to users of APS.

• Collaborators: Beamlines are fully or partially operated by the Consortium for Advanced Radiation Sources Collaborative Access Team (BioCARS-CAT, 14-ID-B, 14-BM-C), the Industrial Macromolecular Crystallography Association Collaborative Access Team (IMCA-CAT, 17-ID-B), the Structural Biology Center Collaborative Access Team (SBC-CAT, 19-ID-D, 19-BM-D), the Life Sciences Collaborative Access Team (LS-CAT, 21-ID-D, F, G), the General Medical Sciences and Cancer Institute Structural Biology Facility (GM/CA-XSD, 23-ID-B, D, 23-BM-B), the Southeast Regional Collaborative Access Team (SER-CAT, 22-ID-D, 22-BM-D), the Northeastern Collaborative Access Team (NE-CAT, 24-ID-C, E), and the Lilly Research Laboratories Collaborative Access Team (LRL-CAT, 31-ID-D).

• Microcrystallography of macromolecular proteins and complexes: GM/CA-XSD (23-ID-B, 23-ID-D), NE-CAT (24-ID-E), and SBC-CAT (19-ID) house world-leading beamlines for MX. GM/CA-XSD provides highly regarded tools for optimal data collection from challenging microcrystals, which often diffract poorly. GM/CA-XSD and NE-CAT offer sophisticated software coupled with a fast-readout area-framing detector to enable rapid sample screening and data collection that minimizes radiation damage. All routinely offer beam sizes down to 5 µm, and GM/CA-XSD and SBC-CAT can provide a 1-µm beam on demand. These capabilities provide key structural details of biologically functional and medically relevant large macromolecular complexes, for which larger crystals can be impossible to obtain.

Collaborators: The NIH and the DOE-BER program

• Time-resolved scattering of partially ordered biological systems: The Biophysics Collaborative

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Access Team (18-ID-D) provides both static and time-resolved structural information on partially ordered systems. Techniques include: solution scattering, fiber diffraction; and combined scanning micro-diffraction imaging, x-ray fluorescence microscopy, and phase contrast imaging for micron-scale imaging of biological tissues.

Collaborator: The NIH

• Time-resolved scattering/diffraction and study of biohazards: The BioCARS-CAT insertion device beamline 14-ID-B supports Laue and time-resolved crystallography and time-resolved solution scattering on time scales down to 100 ps. The dual-undulator, pink-beam capability offers synchrotron world-leading flux of 4 x 1010 photons per 100-ps pulse. Nanosecond- and picosecond-pulsed lasers provide optical stimulation for pump/probe experiments. Beamlines are embedded in a biohazard facility at the BSL3 level, which is unique in the U.S. and one of only two in the world. Physical sciences users at this beamline are supported by the APS.

Collaborators: The NIH, the APS

• Industrial participation: Several pharmaceutical companies have made significant investments to build, upgrade, and operate their own MX beamlines at the APS. IMCA-CAT is a partnership of AbbVie, Bristol-Meyers Squibb, Merck, Novartis, and Pfizer that built and operates 17-ID. Lilly Research Laboratories operates LRL-CAT and the recently upgraded beamline 31-ID.

• The Advanced Protein Characterization Facility (APCF): The recently constructed APCF, which adjoins the APS, has more than 35,000 sq ft of biological laboratories and offices. It is poised to act as a resource to expedite intellectual interactions, scientific exchange, and technological advances.

Collaborators: Potentially, the NIH and other life sciences sponsors

• High-spatial resolution (<50-nm) x-ray fluorescence microscope: The APS and LS-CAT partner to operate the Bionanoprobe (21-ID-D, 30% of available beam time), a unique instrument that offers sub-50-nm resolution and robotic, cryogenic sample transfer capabilities for x-ray fluorescence analysis studies. X-ray fluorescence microscopy (XFM) provides unique quantifiably trace metal imaging within whole cells and tissue sections. X-ray ptychography (20-nm resolution) provides complementary information on cellular ultrastructure.

Collaborators: Northwestern University, the NIH

• Geological materials at extremes: The GSECARS consortium at The University of Chicago operates the 13-ID and 13-BM beamlines, which are used for microdiffraction and tomography of geological materials under pressure, strain, and temperature, and x-ray fluorescence microprobe analysis.

Collaborator: The University of Chicago

• High-spatial resolution spectromicroscopy: For geological and environmental science studies, GSECARS operates two end stations (13-ID-C, 13ID-D) that provide XANES and EXAFS capabilities with 2-µm resolution.

Collaborator: The University of Chicago

Near-term investments: APS-operated beamlines

• Build independent x-ray fluorescence microscopy and spectromicroscopy branches: The APS will reconfigure beamline 2-ID with a cant to produce two independent branches for x-ray fluorescence (XRF) microscopy and micro-spectroscopy, and ptychography. This provides 50-nm spatial resolution in elemental contrast (trace elements) and 10-to-20-nm resolution in structural contrast (absorption/phase) via ptychography. The lower-energy branch will focus on XRF microscopy and

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micro-spectroscopy and carry a large fraction of the current user programs at 2-ID. The higher-energy branch will be used to develop forward-scattering ptychography (in connection with XRF) and push for highest-resolution microscopy. These capabilities can be applied broadly to the life, environmental, chemical, and materials sciences.

Collaborators: The APS will seek a partnership with the DOE-BER program. The ptychography work is in partnership with Advanced Scientific Computing Research, and the Argonne Mathematics and Computer Sciences Division.

CAT-operated beamlines

• Microfocus upgrade for beamline 23-ID-D at GM/CA-XSD: The end station will be replaced with microfocusing optics and advanced goniometry for handling microcrystals, providing a high-intensity beam whose size at the sample can be varied rapidly (few seconds) in the range of 1 to 20 µm in diameter. $2M was provided by the NIH. R&D for the new end station began in 2013 and it will be in operation in early 2016. It will initially be best-in-class and will regain the best-in-class title once the proposed MBA lattice is completed. This upgrade enables the routine use of a beam size as small as 0.5 µm with a 100-fold increase in intensity.

Collaborator: The NIH

• Micro-multiple-line-focus upgrade for 19-ID-D at SBC-CAT: The optics and end station of beamline 19-ID-D will be reconstructed to provide a series of parallel, line-focused beams with ~1-µm width and >5-µm spacing, to reduce primary radiation damage 4-fold.

Collaborators: Funding for these improvements is to be requested from the DOE-BER program and the NIH.

• Microfocus upgrade to 24-ID-E at NE-CAT: Secondary focusing Kirkpatrick-Baez (K-B) optics will be installed in 2015 yielding a 2-by-5-µm minimum beam size.

Collaborators: The CATs and the NIH

• State-of-the-art, high-performance detectors: The fast read-out times and large dynamic range allow shutterless modes of data collection (fine-phi-slicing, rastering, and helical data collection), which improve signal-to-noise and can mitigate the effects of radiation damage. Many MX beamlines have already upgraded their detectors; GM/CA-XSD and LS-CAT will procure new detectors in 2015.

Collaborators: The CATs and the NIH

• Cryogenic x-ray microscopy: Funding will be sought to add capabilities for the study of tissues: cryogenic confocal light microscopy and focused ion beam sample “cutting.” These will allow the APS to reach the full potential of hard x-ray microscopy for 3-D studies of biological materials up to tens of micrometers in thickness, depending on self-absorption limits from lighter or heavier elements. These developments will enhance the cryo-lab facility, which supports cryo-microscopy at the Sector 21 Bionanoprobe and at Sector 2.

Collaborators: Potentially, the NIH and other life sciences sponsors

• High-performance static and time-resolved SAXS: Bio-CAT (18-ID-D) plans to improve high-performance static SAXS with high throughput, larger Q-ranges, and improved data-reduction, processing, and modeling. To improve time-resolved SAXS capabilities for the study of protein and nucleic acid folding and biochemical kinetics, advanced microfluidic mixers will be combined with microbeams, enabling sub-millisecond time resolution SAXS from dramatically lower sample volumes. A high-frame-rate, large-active-area detector will be procured.

Collaborators: Illinois Institute of Technology and the NIH

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• The LS-CAT at Sector 21 plans to refurbish beamline optics to preserve beam coherence: The end station will be upgraded to allow room-temperature rapid data collection from a slurry of crystals using a vertical axis diffractometer.

Collaborators: Northwestern University, Michigan State University, University of Michigan, Van Andel Research Institute, University of Wisconsin-Madison, Vanderbilt University, and University of Illinois at Urbana-Champaign

• The Advanced Protein Characterization Facility: The APCF is currently host to the Midwest Center for Structural Genomics (MCSG), Center for Structural Genomics of Infectious Diseases, and a few other smaller programs. National Institutes of Health funding for the MCSG winds down in 2015. MCSG and SBC-CAT staff are seeking new funding from the NIH and other potential sponsors to continue operation of the APCF as a user facility.

Collaborators: Potentially, the NIH and other life sciences sponsors

Long-term investments: APS-operated beamlines

• Optimize x-ray fluorescence microscopy and micro-spectroscopy branches: Beamline 2-ID will be upgraded including new focusing optics to optimize spatial resolution to 20-nm in elemental contrast (zone plates), and possibly sub-10-nm-resolution fluorescence using multilayer Laue lens optics, or sub-10-nm-resolution imaging via ptychography. These improvements would be accomplished in the 2018 time frame, pending availability of operations funds.

CAT-operated beamlines

• Implementation of a dedicated SAXS/WAXS beamline for biology: The life sciences community wishes to dedicate a best-in-class beamline to solution scattering to meet the growing user demand. This could be developed through a partnership with Bio-CAT, requiring the sector to be canted. The new capabilities would include spatial resolution from 1,000 Å out to 2 Å, and a very-high-speed two-dimensional detector for sub-microsecond time-resolved studies. The proposed MBA lattice would expand the sensitivity and time-resolved opportunities for x-ray scattering techniques.

Collaborators: Bio-CAT; funding will be requested from the NIH and other potential sponsors

• Bionanoprobe-II: Develop a next-generation instrument on a dedicated beamline aimed at delivering rapid, quantitative 3-D information on the role of trace metals in biological systems through further development of cryogenic sample preparation capabilities, higher-speed fluorescence tomography, improved tomography capabilities with an eccentric rotation stage, correlative cryo-confocal light microscopy, and improved algorithms for combined ptychographic and fluorescence image reconstruction.

Collaborators: Potentially, the NIH and other life sciences sponsors

• Dedicated fixed-energy nanoprobe: To exploit the proposed MBA lattice and meet growing user demand for a dedicated nanoprobe, LS-CAT plans to fix the energy of the 21-ID-E inboard undulator at 12.6 keV and replace the detector.

Collaborators: LS-CAT; funding will be requested from the NIH and other potential sponsors

• Performance improvements to 24-ID-C,E at NE-CAT: To exploit the proposed MBA lattice, the vertical focusing mirror on 24-ID-E will be replaced and the monochromator on 24-ID-C upgraded to improve stability. These are to be completed in 2017.

Collaborators: The CATs and the NIH

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6.4 Enabling Technologies for X-ray Science Many planned improvements impact multiple beamlines. Those deemed a priority for investment during the next five years are highlighted in this section.

Science at the APS relies heavily on beamline and end station instrumentation: optics for x-ray energy, bandwidth, coherence selection, and focusing; detectors for photon counting, dispersive analysis, and imaging; and experimental equipment for providing a wide range of environmental conditions as well as sample and detector positioning. While preparing for a proposed MBA-upgraded APS, new instrumentation and techniques must be developed to fully exploit the new source parameters to make optimal use of the revolutionary 100-1,000x increase in brightness, coherent flux, and detected signal. 6.4.1 Optics, Detectors, Data Collection and Analysis Optics

The APS utilizes high-quality x-ray optics to deliver the x-ray beam to the sample and in many cases to collect the relevant signal from the experiment, such as when using crystal analyzers. But as noted in the 2013 workshop report, “X-ray Optics for BES Light Source Facilities,” the development of ever more powerful x-ray sources in the near future require a new generation of x-ray optics that allow us to fully utilize these beams of unprecedented brightness. The APS Optics Group coordinates with other DOE light source facilities to develop this required next-generation optics by leveraging the unique APS R&D capabilities described below.

Leading or unique capabilities: • Simulation tools for optimizing the design of beamline optics: The development of a rapid “hybrid

method” for combined ray tracing and wavefront propagation in the widely used program SHADOW [Shi et al., J. Synchrotron Rad. 21, 669 (2014)] complements slower first-principles simulation tools. This enables the design of beamline optical layouts optimized for next-generation sources.

• Production and metrology capabilities for brightness-preserving x-ray mirrors: The APS has a new, best-in-class long-trace profilometer for mirror characterization at the less than 0.05 µrad slope errors required for use with new-generation x-ray sources.

• Production and characterization capabilities for crystal optics: The APS is the only DOE light source with a full suite of fabrication and characterization capabilities for crystal optics. This unique set-up was made even more useful and innovative with the recent hire of an expert on improved crystal polishing methods, and the development of the 1-BM Optics and Detectors Test Beamline for crystal topography and at-wavelength interferometry. The preservation of coherent flux and crystal analyzers performance for 0.1- to 10-meV energy resolution spectroscopy requires crystal optics with reduced surface roughness and internal strain or dislocations.

Near-term investments: • Build a new modular deposition system with in situ metrology capabilities to produce reflective

optics to meet MBA requirements, which will be equipped to measure the figure of existing mirrors up to 1.5 m long and correct their profiles. This allows for the refurbishment, rather than replacement, of many APS mirrors, which can save tens or hundreds of thousands of dollars per mirror, depending on mirror size and desired performance parameters.

• R&D into high-efficiency, hard x-ray zone plates for nanofocusing: The proposed APS Upgrade will require zone plates that can focus to 25 keV and have a sub-20-nm resolution. The current R&D program in hard x-ray Fresnel zone plates has achieved 19% focusing at 25 keV by stacking multiple zone plates. This is an improvement from the 2.4% focusing of a single zone plate.

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Collaborators: Leverage the atomic layer deposition expertise at the Argonne CNM and in the Argonne Energy Systems Division, as well as the nanofabrication capabilities at the CNM to conduct the R&D work.

• Development of advanced multilayer Laue lenses: The optics R&D work at the APS (mentioned above) complements the development of lenses aimed at sub-10-nm focusing at fixed hard x-ray beam energies, and kinoform refractive lenses for focusing 20- to 60-keV beams. The combination of these advances in optics technology will be the key to the success of next-generation high-energy probes for materials and chemical science.

Collaborator: Brookhaven National Laboratory

Long-term investments: • Research and development for high-performance diamond crystals: The low absorbance and high

thermal conductivity of diamond offers important characteristics for hard x-ray applications. The APS has an active program of collaboration with several developers of thin-film diamond crystals. The topographic characterization and experimental design is being done in-house. This work will support future needs for high-heat-load monochromators and rapid helicity-switchable polarizers at the APS.

Detectors The 2012 BES workshop report, “X-ray and Neutron Detectors,” noted: “While impressive breakthroughs in x-ray and neutron sources give us the powerful illumination needed to peer into the nano- to mesoscale world, a stumbling block continues to be the distinct lag in detector development, which is slowing progress toward data collection and analysis.” The APS Detectors Group works in collaboration with other DOE facilities to reduce that lag.

Leading or unique capabilities: • High-count-rate, energy-resolving detectors with few-eV spectroscopic capabilities: The APS will

work toward development of a 1,000-pixel, 100-kHz maximum count-rate prototype superconducting detector to combine nanoscale focusing with x-ray emission spectroscopy. This complements the ~150-eV energy resolution of commercial silicon drift diodes, which can handle count rates of more than 1 MHz for bulk analysis of major constituents. The potential creation of a Detector Center at Argonne will aid this effort toward pixelated superconducting detectors. This work is made possible with the initial support from a DOE Early Career Award.

Collaborators: Cosmology and x-ray science superconducting detector efforts at Argonne, SLAC National Accelerator Laboratory, and the National Institute of Science and Technology (NIST)-Boulder Laboratories.

• Widespread availability and support of detectors for beamline experiments: The APS Detector Pool provides detectors that individual beamlines do not use frequently enough to justify purchasing on their own, thus saving money through shared ownership. The pool staff helps users set up these detectors, and coordinates the evaluation of new commercial detectors.

• Characterization to support the development of new detectors: The development of new detector technologies requires frequent testing to evaluate various approaches and improvements to electronics. The Detector Pool team coordinates tests at APS beamlines of prospective detectors, such as high-energy CdTe-based detectors from Pixirad. The 1-BM Optics and Detectors Test Beamline provides a way for the APS to keep abreast of the latest advances in x-ray technology by collaborating with sister laboratories, academia, and industry. The test beamline has been used for internal development programs and for tests of promising new detectors. Collaborative testing

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includes the AGPID charge-integrating pixel array detector being developed jointly by DESY (Deutsches Elektronen-Synchrotron, Germany), Paul Scherrer Institute (Switzerland), and the University of Hamburg (Germany); and prototype commercial scintillators from RMD and Agiltron. Collaborators: Various industry, academic, and government entities

Near-term investments: • High-rate detectors for online analysis in XPCS: High frame rates are required for pixelated detectors to

study the dynamics of materials at millisecond or faster timescales. In a collaboration led by Lawrence Berkeley National Laboratory, the APS has developed the back-end electronics for new, highly column-parallel readout CCD detectors that can operate at partial-frame rates of up to 1 kHz. Now that the basic operation of the detector has been established, work is under way to develop parallelized code that runs in the detector’s control crate to do region-of-interest autocorrelation analysis and enable real-time interpretation of XPCS data.

Collaborator: Lawrence Berkeley National Laboratory

• Vertically integrated photon imaging chip detector: New 3-D fabrication approaches will be applied to the DOE-funded development of the vertically integrated photon imaging chip (VIPIC) detector, a pixel array detector that can provide on-detector auto-correlation analysis for real-time evaluation of XPCS signals with microsecond time resolution.

Collaborators: Brookhaven National Laboratory and Fermi National Accelerator Laboratory

• Germanium strip detectors for energy-dispersed and powder diffraction: One-dimensional detector arrays are needed both for energy-dispersed diffraction experiments and for high-throughput powder diffraction experiments, which play an essential role in evaluating new materials. The APS is part of a DOE-funded collaboration to produce low-noise, energy-discriminating readout electronics for Semikon-developed Germanium sensors with improved energy resolution and performance at high x-ray energies compared to silicon. The APS is positioned to handle the mechanical design of detectors optimized for APS beamlines and participate in sensor and readout electronics testing and characterization using the 1-BM Optics and Detectors Test Beamline.

Collaborator: Brookhaven National Laboratory

Long-term investments: • High-dynamic-range, gap-free pixel array detectors for real-time x-ray diffraction measurements: The

high per-pulse brightness of an upgraded APS will lead to strong signals in Bragg peaks, but it is still desirable to record the much weaker diffuse scattering signal. Because multiple photons can arrive in one Bragg peak per electron bunch in the storage ring, one must go with charge integrating rather than photon counting readout electronics. Fermi National Accelerator Laboratory has developed a unique circuit design for this with 10-fold improvement over what has been demonstrated at any other facility. To take advantage of that circuit design, the APS has initiated an R&D program to develop FASPAX, a pixel array detector with additional unique features that include a gapless, wafer-sized sensor design to allow for capture of full diffraction patterns with no missing regions (with an interposer layer for coupling to application-specific integrated circuits or ASICs) and on-pixel analog charge storage to allow for movies to be recorded of dynamic processes with a burst frame rate of 13 MHz. The goal of the R&D is to evaluate the performance of this prototype as the first in a possible series of APS-optimized pixel array detectors, complementing detector developments at other light source facilities.

Collaborator: Fermi National Accelerator Laboratory

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Data Collection and Analysis The bulk of APS instruments have grown organically; as techniques and detectors have improved, they have been adopted into data collection practice to keep instrumentation at the state of the art. Software development, both for operating beamlines and for analysis of the resulting data, has struggled to keep pace. Coupled with this has been a growth in techniques that create huge amounts of data: X-rays are ideally suited to the study of real materials operating under real conditions in real time. However, real materials are often complicated, showing hierarchical organization across length scales from nanometers to centimeters. As a result, the information obtained from x-ray measurements is increasingly too rich to understand by simple examination. In addition, the APS produces one of the highest data volumes of any research facility in the nation — about 200 TB per month. This volume will grow dramatically in the near future due to advanced optics and detectors. (The speed and quantity of data growth depends on the types of detectors implemented.) Because of the huge diversity of the APS user community, there is a multitude of data analysis tools and programs in use at the APS (see https://www1.aps.anl.gov/Science/Scientific-Software/).

Here are a few examples of new developments amongst a large number of activities:

Leading or unique capabilities: • Small-molecule crystallography and powder diffraction analysis: The General Structure Analysis System

(GSAS) is an analysis program that dates back to 1985, with more than 6,000 citations in the literature. The APS has supported the development of a more modern successor, GSAS-II, with a graphical user interface and a Python code-base. GSAS-II is becoming widely used for both synchrotron and laboratory x-ray analysis, as well as for neutron crystallography.

• Workflows for the reconstruction of multimode tomographic data: X-ray computed tomography for 3-D imaging is employed at a large number of APS beamlines, across length scales ranging from nanometers to centimeters, and in multiple modalities. The APS has developed TomoPy as a reconstruction package for tomography workflows [Gursoy et al., J. Synchrotron Rad. 21, 1188 (2014)] using Scientific Data Exchange as a schema for data organization in HDF5 files [De Carlo et al., J. Synchrotron Rad. 21, 1224 (2014)]. This software package is being adopted at a number of light source facilities worldwide, including at the Lawrence Berkeley and Brookhaven national laboratories.

• High-speed data transfer using Globus: Users of the APS almost invariably wish to take their data home with them at the conclusion of an experiment, but datasets are becoming so large that even the act of copying them to portable hard drives or flash drives can become problematic. Argonne and The University of Chicago have developed Globus Online as the first of a suite of Globus tools. Globus Online uses multiple parallel network connections (if available) to arrange for robust, high-speed transfer of data from Argonne to user home institutions.

Collaborator: The University of Chicago

• Leading facilities for novel beamline access: GM/CA-XSD and many other APS macromolecular CATs have pioneered sophisticated remote and mail-in access modes of operation and have leading control systems. The high-resolution and high-throughput 11-BM powder diffraction beamline has further automated beamline operations and demonstrated that this can greatly improve instrument utilization in the chemistry and materials communities.

Near-term investments: • High throughput, online data analysis: Experiments in x-ray diffraction microscopy, x-ray diffuse

scattering, x-ray photon correlation spectroscopy, and x-ray ptychography are leading examples of techniques where software tools, such as PtychoLib, are being developed to enable online data analysis for immediate comparison with simulations. Development of these analysis tools is being aided by the

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use of Argonne and University of Chicago-developed tools, such as the Swift parallel scripting language, to enable easy utilization of cluster computers, and highly optimized code using graphical processing units (GPUs) on workstations for 100-fold or more analysis speedup. For example, advances of GPU and cluster computing were combined to yield a ten-thousand-times speedup in x-ray ptychography reconstructions while using a different algorithm with multiple probe mode and stage position error recovery capabilities compared to code developed at other national laboratories. Collaborators: PtychoLib was developed with support from DOE-ASCR and DOE-BES, and involves interested users from the Pacific Northwest, SLAC, Lawrence Berkeley, and Brookhaven national laboratories.

• Data storage, distribution, and analysis: Argonne has recently implemented a 1.7-petabyte data storage service “petrel” with Globus endpoint capabilities. With Argonne funding support, an automated data management system is being piloted to bring data from beamline computers to “petrel” (Figure 6.4.1). This can also be accessed by the parallel file system used by Argonne’s supercomputer, Mira, paving a path towards immediate online analysis of large datasets and comparison with simulations.

Collaborators: The Argonne Mathematics and Computer Science Division and the Argonne Leadership Computing Facility

• Beamline data collection frameworks: The APS has started work on easy-to-use control interfaces utilized to operate beamlines. When deployed they allow for more intuitive and efficient operation by users and decrease the workload for beamline scientists by automating commonly performed manual tasks. These software building blocks (frameworks) need further development and generalization, as well as additional feedback from users to guide improvements as they are installed on beamlines that are being redeveloped. This will result in a set of tools that can be employed on most APS beamlines and will also allow software-upgraded beamlines to have a common look-and-feel, benefiting users of multiple techniques.

• Generalized mail-in automation: Based on the experience gained from the macromolecular beamlines and 11-BM, a software package is needed that will allow bringing mail-in access to many more beamlines, where a subset of their operations can sensibly be offered in that mode.

Long-term investments: • Cloud computing and virtualized analysis: Increasing data volumes and analysis program sophistication

require dramatically increased resources for beamline data pipelines. They also make it problematic for some users to ship data home and analyze it if they have insufficient computing resources at their own institutions. The APS is working with the CELS directorate at Argonne to configure preemptive scheduling that will allow beamlines to rapidly complete computations on large-scale hardware, while making idle cycles available for other Lab research. Further, users will be aided through access to

Figure 6.4.1. The APS is developing a pilot data management system to enable rapid data analysis using high-performance computing resources. Data will be automatically transferred (organized by experimental team) to storage resources within the APS. Data will then be transferred to a Laboratory-wide data storage system (petrel) where it can be accessed automatically by Argonne’s leadership-class computing facilities.

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technique-specific analysis programs, along with remote visualization tools such as ParaView, on virtualized servers located at Argonne. This approach brings users virtually to their data rather than requiring huge datasets to be transferred to their home institution.

Collaborators: The Argonne Mathematics and Computer Science, and Leadership Computing divisions

• Moving from data analysis to scientific understanding: The APS will forge a program to address the need for advanced analysis techniques. With higher-speed detectors, and especially an upgraded APS, one can expect to obtain increasingly rich datasets at higher resolution and in 3-D [de Jonge et al., Proc. National Acad. Sci. 107, 15676 (2010)]. What is really wanted is to go beyond these quantitative maps to glean scientific understanding, for example by automatically identifying individual cell types and carrying out statistical analyses of their composition [Wang et al., J. Synchrotron Rad. 21, 568 (2014)].

Collaborators: The Argonne Materials Science, and Mathematics and Computer Science divisions

• Beamline data collection refresh: A systematic effort will be made to bring updated beamline operational software, in terms of updated control software, workflow tools and where appropriate mail-in operation to all existing beamlines, in addition to those being upgraded. With existing staffing levels, only a few beamlines can be addressed each year.

6.4.2 Beamline Engineering In order to study real materials under real conditions in real time, the materials must be placed in an environment that captures their working conditions, including pressure, fluids, temperatures, and fields. This becomes particularly challenging in nanofocusing applications where complex environments must be combined with positional stability, minimal vibrations, and short working distances. With the proposed APS upgrade to a MBA lattice, these characteristics must be combined with unprecedented rapid-scan times to fully exploit beam brightness in nanoprobe experiments.

Leading or unique capabilities: • In situ and in operando sample environments: The APS staff has acquired considerable expertise in

developing diamond anvil cells for high-pressure research, particularly those suited for operation at low temperature and in high magnetic fields, in contrast to the more standard cells that are of interest to the geoscience community and that allow interrogation of samples at high pressures and temperatures. This work often has been done in partnership with HP-CAT.

• For studying materials such as battery electrodes in the presence of fluids or electrolytes, staff from the X-ray Science and APS Engineering Support divisions have developed AMPIX (Argonne Multi-Purpose In Situ X-ray), an environmental chamber that has helped attract high-profile users to the APS.

• A variety of sample ovens and structural failure testing environments have been developed for x-ray tomography and diffraction microscopy of dynamic samples.

Collaborator: HP-CAT

• Cryogenic sample preparation and environments: Hydrated soft materials, including biological specimens, can experience a dramatic reduction in sensitivity to radiation damage when put in cryogenic conditions. The APS has a Cryogenic Sample Preparation Laboratory, which is supported by the NIH through Northwestern University; and the Bionanoprobe, operated at the LS-CAT beamline, a first-of-its-kind cryogenic x-ray fluorescence microscope with robotic cryogenic sample exchange capabilities.

Collaborators: Northwestern University, Carl Zeiss X-ray Microscopy, and LS-CAT

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Near-term investments: • The APS is supporting a Small Business Innovation Research project by Hummingbird Scientific to

adapt environmental chambers developed for electron microscopy to the needs of x-ray nanofocusing experiments.

Collaborator: Hummingbird Scientific

• High-speed, high-accuracy specimen scanning: Instruments such as x-ray nanoprobes and ptychography experiments involve per-pixel measurement times down into the microsecond range and pixel increments on the nanometer scale. To meet the high scanning-speed requirements of the future, the APS is developing new nanopositioning instrumentation and control systems, including the use of feed-forward control concepts. This work is being carried out in close communication with complementary nanopositioning R&D activities at the Brookhaven and Lawrence Berkeley national laboratories.

Collaborators: The Brookhaven and Lawrence Berkeley national laboratories

Long-term investments: • High-stability beamline and optics design: To take advantage of and preserve the high brightness

available at an upgraded APS, more-stable beamline components, such as monochromators, mirrors, and slit assemblies must be developed. Engineering these systems for specific beamlines is part of the proposed APS Upgrade. It is expected that these advances will be leveraged for improvements to other beamlines not in the proposed APS Upgrade scope.

Collaborator: The APS Upgrade Project

6.4.3 R&D for X-ray Techniques Greatly Improved with the Proposed APS Upgrade The proposed incorporation of a MBA lattice at the APS promises to dramatically improve several coherence- and high-energy-based techniques such as hard x-ray nanoprobes, phase contrast imaging, x-ray photon correlation spectroscopy, coherent diffractive imaging and ptychography, and nanoscale high-energy diffraction. In each area, research and development is required to position the upgraded facility to optimally and immediately use these capabilities after the upgrade is accomplished.

Hard X-ray Nanoprobes Hard x-ray nanoprobes focus the coherent x-ray beam into an optic-limited spot, through which the sample is raster-scanned. A variety of detectors provide a custom combination of contrast modes, including absorption, phase contrast, x-ray fluorescence (trace element mapping), and diffraction (structural information including stress and strain). In combination with sample rotation, these contrast modes can also be used in tomographic reconstructions.

At the APS, nanoprobes use either zone plates to produce x-ray beams down to 20 nm in size or achromatic K-B mirrors to focus down to 100 nm. Additionally, a multilayer Laue lens-based prototype microscope has demonstrated spatial resolutions better than 30 nm with 17% efficiency at 20 keV.

The proposed APS Upgrade will revolutionize scanning x-ray microscopes. The increased brightness provides a 100-fold increase in focused flux and correspondingly faster data acquisition. This enables the routine use of tomographic approaches to study extended objects in 3-D at the highest spatial resolution. Combined with advanced reconstruction techniques now under development that will further reduce the required photon dose per projection, this will enable, for the first time, high-fidelity tomographic datasets with 20-nm spatial resolution and improved fields of view (millimeters). However, considerable R&D is required to exploit the scientific opportunities an upgraded APS provides.

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R&D Work • Stable, rapid-scanning nanoprobe platform: This is a joint need for CDI and ptychography. • Development of focusing optics: Targets for development include high-resolution, high-efficiency

zone plates with stacking mounts; and high-resolution, low-background, achromatic, nanofocusing K-B mirrors with zoom lenses and mounts. These needs overlap with those of CDI, ptychography, and phase contrast imaging (PCI).

Collaborator: The APS Upgrade Project

• Algorithm development for data analysis: R&D is required in dose fractionation to minimize radiation damage and data acquisition time for advanced iterative reconstruction algorithms to enhance the fidelity of tomographic reconstructions of noisy images, and for model-based reconstruction approaches that can correct for placement errors during data acquisition.

Collaborators: The Argonne Mathematics and Computer Science Division, and BAE Systems

• Detectors with spectroscopic energy resolution: Development of detectors that enable detection of x-ray fluorescence signals with energy resolution down to eV significantly increases sensitivity for trace element detection and visualization. It may also open the possibility of x-ray emission spectroscopy, potentially the only viable approach to spectroscopy of trace elemental content at resolutions less than 20 nm. Research and development in superconducting detectors toward these goals in the hard x-ray regime is being pursued through a DOE Office of Science Early Career Research Program effort in the XSD Detectors Group, as described under Detectors.

Collaborators: The new Argonne Detector Center/The University of Chicago, NIST, and SLAC National Accelerator Laboratory

Phase Contrast Imaging The small, round beam of the MBA-upgraded APS will enable development of a high-performance projection microscope using full-field propagation-based PCI. Phase contrast imaging, a real-space imaging technique, can increase sensitivity by several orders of magnitude in situations where absorption contrast is limited, e.g., interrogation of low-Z materials at high photon energy to reduce radiation damage. The projection microscope features zoom-in/zoom-out capabilities with resolution limited by the focal-spot size and variable field of view controlled by focus-to-specimen distance (Figure 6.4.3.1).

For two-dimensional images, an upgraded APS allows one to obtain movies with polychromatic illumination at a 13-MHz frame rate with vastly enhanced resolution (Figure 6.4.3.2.). These stroboscopic capabilities are desirable for studies in fluid dynamics and materials under extreme conditions. For 3-D images, one may use tomographic techniques where the enhanced flux in an APS upgraded with a MBA lattice, coupled with a projection microscope system, enables users to obtain full 3-D datasets at 100 Hz with 100-nm resolution for time-resolved studies. This represents a 1,000-fold improvement relative to the current dynamic tomography studies at the APS, where routine data collection occurs at 1 Hz with 1,000-nm resolution across a 1-mm field of view.

Figure 6.4.3.1. Concept of the full-field phase contrast projection microscope. Courtesy of Xianghui Xiao, Argonne National Laboratory

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One can envision a PCI-enabled beamline that operates in two modes: polychromatic, including projection microscopy, for single-shot exposures; and monochromatic, including stereo imaging. The polychromatic mode will feature field-of-view up to ~30 x 10 mm, resolution of 10 µm to 0.1 µm, as determined by upstream focusing optics; and exposure times down to ~100 ps for single-shot, 2-D freeze-frame images. The images are collected using scintillators coupled with ever-improving commercial framing cameras (e.g., frame rate of 5 MHz with 180 frames).

In a monochromatic x-ray stereo imaging mode, one will be able to obtain 3-D information on samples without resorting to sample rotation. With the monochromatic beam and stereo view,

one would be able to obtain two images simultaneously with different viewing angles (10o to 40o) using ~millisecond exposure times. These two views could be used to obtain 3-D information on the sample with resolution on the micron level and field of view in the millimeter range to study dynamics occurring on millisecond timescales.

R&D Work: • Algorithm development for efficient data reduction: To extract 3-D information from the stereo

view and integrate multi-scale (temporal and spatial) 3-D imaging, specialized algorithm development is necessary.

Collaborator: The Argonne Mathematics and Computer Science Division

• Simulations of optical aberration effects on data quality: Wavefront preservation for phase contrast imaging is critical, but given that perfection is not attainable, optics simulation tools that take into account wavefront distortion are required and are being developed by the XSD Optics Group.

• Optics: The full-field projection microscope benefits from improved optics that minimize wavefront distortion. Focusing of a polychromatic, high-energy x-ray beam with coherence preservation is critical. It is anticipated that the new modular, multilayer mirror deposition chamber under development in XSD will play a key role as one investigates various possibilities, e.g., profile-coated, multilayer K-B systems, and multilayer Laue lenses. High numerical aperture, achromatic, or broad bandwidth optics that can focus a beam smaller than 50 nm is especially desirable for both full-field imaging and the integration of multimodal techniques.

• Detectors: Commercial fast-framing cameras that operate in the visible regime and are coupled with scintillators are used in phase contrast imaging research, which will benefit from research to improve the speed and efficiency of scintillators, including using columnar scintillators. Current decay time is 50 ns, but a few nanoseconds are needed to reduce cross talk between x-ray pulses.

Collaborators: Various industry partners

X-ray Photon Correlation Spectroscopy XPCS uses coherent x-ray scattering to provide sensitivity to the exact arrangement of particles within the coherently illuminated sample volume, yielding a complete picture of the structure in a sample. This information manifests itself in the x-ray scattering image as bright and dark intensity modulations, called

Figure 6.4.3.2. Source size effects in phase contrast imaging as illustrated by simulated x-ray images of an air bubble (2-μm diameter) inside a water drop (0.4-mm diameter) in air at 15 keV. (a) The drop viewed with the current APS lattice, and (b) expected image with the future MBA lattice at the APS. Courtesy of Kamel Fezzaa, Argonne National Laboratory

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“speckle.” Fluctuations in the structural, chemical, or magnetic order in the material result in fluctuations in the speckle pattern. The time scale on which one can view fluctuations is presently limited to the millisecond range by detector readout rate in the small-angle scattering regime and to the seconds range by coherent photon flux at wide angles. The 100-fold increase in source brightness provided by a MBA lattice can provide increased dynamic range and potentially reach simultaneous time and space resolutions of a nanosecond and nanometer.

The APS offers users the luxury of relatively bright bunches separated by relatively large pulse separations (~100 ns). While the APS is typical among many third-generation synchrotron sources in having x-ray beams with a transverse coherent fraction of ~10-3 and pulse lengths of ~100 ps that will change with the proposed APS Upgrade to a unique transverse coherent fraction of ~0.1. The APS has the opportunity to develop XPCS and time-resolved coherent scattering methods to access a uniquely broad span of time delays encompassing 100s of nanoseconds to 1,000s of seconds. To reach these x-ray photon-limited specifications, considerable R&D in detectors and data analysis/computation is required.

R&D Work: • High-performance computing workflow development: Acquisition of a commercial Eiger detector

will enhance the frame rate by 30x more than the available system and spur the development of software to map the associated data stream to high-performance computing (HPC) systems. Live, as opposed to batched, big data/HPC processing of detector data streams is required. This includes compression, sparsification, and correlation computation. Simple compression yields a data reduction of 10x to100x. This would increase to 100x to 1,000x with live sparsification.

• Detector development: Direct x-ray photon counting detection is used for XPCS studies. Optimized detectors will feature high-gain, low-dynamic-range pixel detection (~50- to 80-µm pixel size), dead-time-less readout, shaping times less than the bunch spacing to prevent pileup, frame spacing of one turn (3.5 µs), and sparse readout. This represents a ~1,000-fold improvement as present frame spacing is limited to a few milliseconds. An R&D effort in this direction includes the VIPIC detector with on-chip data analysis.

Collaborators: The Brookhaven and Fermi national laboratories funded through BES, and several universities

Coherent Diffractive Imaging and Ptychography Coherent diffractive imaging uses coherent x-ray scattering and iterative-phase retrieval to provide 2-D and 3-D images with a resolution that is only diffraction and dose limited. Coherent diffractive imaging, a reciprocal-space technique, has demonstrated a world-best resolution of 3 nm using a 1 µm spot size on an isolated object [Takahashi et al., Phys. Rev. B 80, 054103 (2009)] and with ptychography, e.g., use of overlapping measurements on an extended sample for phase retrieval, and a resolution of 5 nm using a 60-nm spot size in 2-D [Shapiro et al., Nat. Photon 8, 765 (2014)]. With the extended depth of focus available through ptychography, one can envision imaging extended 3-D objects with 5-nm voxel sizes. These heroic experiments will become routine with the proposed upgraded APS and the planned R&D outlined here. Coherent diffractive imaging will be transformed by the proposed upgraded APS, where the increased brightness provides a 100-fold increase in focused flux. Combined with a recently developed 200-fold more efficient ptychographic reconstruction method [Nashed et al. (2014) submitted], this translates to a 20,000-fold increase in throughput. The APS staff aspires to reach a routinely attainable resolution of 2 nm on an extended sample with ptychographic techniques. Considerable R&D is required to exploit the scientific opportunities the proposed upgraded APS will provide in the area of nanofocusing. All scanning microscopes at the APS use scanning systems that are compatible with per-pixel dwell times of about 1 msec or longer and stability at the 10-nm level. To make full use of an upgraded APS, per pixel transit times must be up to a thousand times shorter, and positioning accuracy needs

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to become ten times smaller. This speed-up in data collection will necessitate considerable R&D for improved data analysis and computation and detector data pipelines. Collaborator: The Argonne Mathematics and Computer Science Division

R&D Work: • Rapid-scan nanoprobe platform: Systems are designed for static stability rather than for dynamic

scanning. These systems utilize long-range piezodrive systems and have long mechanical paths, which are counterproductive to the goal of a small, light, stiff system to couple the optic to the specimen. A specialized control system that incorporates feedback and feed-forward to accurately generate the desired motion trajectory must be developed.

• Algorithm development for data reduction and analysis: Development of phase retrieval algorithms that are able to handle experimental uncertainties, photon statistics, and beam fluctuations is required. Using coherent imaging and the phase of the sample, one can do the equivalent of XANES, but the data cannot be analyzed. Development of ways to analyze five-dimensional datasets will enable future ptychoprobe studies, such as ptycho-XANES-tomography on a battery during cycling. This dataset needs phase-retrieval and chemical-state analysis, tomography, and registration, which are performed in serial today but must be automated. Combining multimode datasets will increase information content. For example, fluorescence data can be used to further constrain ptychography, spectromicroscopy, and SAXS data.

Collaborator: The Argonne Mathematics and Computer Science Division

• Workflow and data pipelines: As data rates increase at least 100-fold due to the increase in brightness with the proposed APS Upgrade and phase retrieval becomes more sophisticated, moving data and processing it in real time will become more challenging. Software tools, such as PtychoLib, are being developed to enable online data analysis to inform the progress of an experiment during execu-tion. Argonne- and University of Chicago-developed tools enable easy use of cluster computers and highly optimized code using graphical processing units (GPUs) on workstations for 100-fold or more analysis speedup. For example, advances of GPU and cluster computing combined to yield a 200-fold speedup in x-ray ptychography reconstructions, enabling the development of ”fly-scan” ptychography, in which the sample is in continuous motion, thus eliminating motion overhead and reducing total measurement time by up to a factor of 10. Continued development along these lines is anticipated. Collaborators: The Argonne Mathematics and Computer Science Division, and The University of Chicago

• Optics and detectors hardware: Coherent diffractive imaging ptychography instrumentation benefit from improved condenser lenses (e.g., zone plate development for hard x-rays) and detectors with faster frame rate, smaller pixel sizes, and higher dynamic range.

Collaborator: The APS Upgrade Project

Nanoscale High-Energy X-ray Diffraction The bulk penetration of high-energy synchrotron x-rays combined with high spatio-temporal resolution, provides unique capabilities for non-destructively measuring the phase, texture, and strain distribution of real-life polycrystalline aggregates under relevant in operando conditions, such as high pressure, thermo-mechanical loading, or irradiation.

The APS provides users with several leading high-energy structural characterization tools for probing bulk systems, such as HEDM, SAXS, WAXS, PDF, XRD, and dynamic phase-contrast tomography. These techniques are frequently used in combination with each other to provide hierarchical information across a broad range of length scales from the same micron-level volume. Understanding the dynamic mesoscale behavior of such systems and how the individual crystalline grains interact, grow, reorient, and redistribute stresses requires further improvements in spatial resolution from the current few-micron spot size. The proposed APS Upgrade will afford just such capabilities since the dramatic increase in brightness can

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directly translate into significantly smaller high-energy beams with increased flux. However, realizing nanoscale beams requires commensurate improvements in high-energy optics. As the photon energy increases, deploying efficient x-ray focusing optics becomes more challenging due to the increasingly finer features required for fabricated structures, the weaker refractive effect, and smaller incidence angles. Research and development is required to advance flexible high-energy optics capabilities to take full advantage of an APS upgraded with the MBA lattice.

R&D Work: • Refractive high-energy optics: During the past several years, the APS Materials Physics and

Engineering Group has developed “saw-tooth” refractive lenses to provide ~3-µm beams at ~100 keV for high-energy applications. Significant improvements in the quality of the saw-tooth profile are required, however, to achieve submicron focusing with these types of lenses. Furthermore, new methods to correct for aberrations introduced via bending and/or adjusting the gradient of the saw-tooth pitch must be tested. Kinoform lenses provide an alternate refractive optic for high-energy focusing. Submicron (0.2- to 1-µm) focusing has been demonstrated across energies of 50 to 65 keV, but with only a relatively small horizontal acceptance (0.1 mm) compared to the millimeter-scale beam size. Improved fabrication techniques must be developed to increase the aperture sizes in order to collect all of the available photons.

Collaborators: Brookhaven and Los Alamos national laboratories

• Reflective high-energy optics: Focusing schemes utilizing multilayer optics in K-B geometry may provide a route toward nanoscale focusing at high x-ray energies. Maintaining a high degree of layer uniformity with commensurate high x-ray reflectivity, while simultaneously producing the correct figure for the profile coating in the multilayer, is technically challenging. This R&D need overlaps the requirement for phase contrast imaging. Methods for manufacturing such optics will be developed by the APS Optics Group in collaboration with APS staff at high-energy beamlines.

• Analysis and management of large data sets: The increased resolution that will be provided by the MBA lattice for techniques such as HEDM, coupled with faster detectors for dynamic measurements, will lead to extremely large data sets (>10 TB/day). New integrated approaches toward both data handling and processing that use high-performance computing must be developed in order to both manage the data volume and provide near real-time results for experiments at the beamline. Initial projects to both process and store these large data sets at the Argonne Leadership Computing Facility are currently being pursued.

Collaborators: The Argonne Mathematics and Computer Science Division, and the Argonne Leadership Computing Facility

7 Accelerator Operations and Improvements The accelerator system is the backbone of the APS scientific program. Excellent technical design, best-practice engineering, a demanding quality-assurance program, and a stringent preventive maintenance policy have yielded a reliable accelerator complex that operates with a level of machine availability that typically exceeds 97% of scheduled user hours. The accelerator system also continually undergoes improvement to keep the APS competitive with leading global x-ray sources and to meet the changing needs of scientific users.

The APS accelerator complex consists of the 7-GeV, 1.1-km storage ring operating with a 100-mA electron beam; the full-energy booster synchrotron; the 400-MeV particle accumulator ring; the 400-MeV pulsed linac; and the S-band rf thermionic electron gun. The APS has the largest number of installed 352-MHz CW rf power systems in the U.S. and the second largest installation of pulsed S-band rf power.

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The APS faces a unique challenge during the next five years. Many accelerator components are quickly approaching or have exceeded their lifespans. At the same time, the APS is preparing to enter a new era where numerous world-leading synchrotron x-ray sources will transition to nearly diffraction-limited light sources by implementing a MBA lattice concept. The APS is in the midst of developing a technical design for the MBA lattice and proposes to begin operation of a new source in the 2020s.

The five-year operations plan for the APS accelerator system integrates an end-of-life plan for accelerator components that maintains the very high level of APS performance and reliability with R&D and installation plans for the development of a MBA lattice-based source. This alignment of near-term accelerator improvements with the long-term transition to a MBA lattice source will reduce maintenance costs while accelerating installation of the proposed MBA-upgraded APS.

The accelerator operations plan meets the current and future capability needs expected of a world-leading light source while maximizing efficiencies and delivering high beam availability to users. In assembling this plan, it was presumed that the present APS storage ring will stop operation approximately the 2020’s and be replaced by a MBA lattice. Thus, careful provision was made to differentiate between equipment and accelerators in the APS accelerator complex that will continue to operate in a MBA-upgraded storage ring, versus the equipment and accelerators that will not. This is accomplished in three main areas:

• Accelerator reliability • Accelerator improvement • Accelerator R&D to advance new concepts and next-generation light sources

7.1 Accelerator Reliability Maintaining reliable operation of an aging accelerator is not an easy task. Replacement of obsolete components, end-of-the-lifetime equipment, and consumable parts is a permanent mission requiring significant resources. The goal of APS staff and management is to ensure that this is done in the most cost-effective and efficient manner. This involves an on-going interaction of technical staff and management to assess risks to reliable operation and to prioritize activities targeting high-risk issues. For example, in the area of safety interlocks, the plan is to replace obsolete and life-expired access control interlock system components as well as front-end equipment protection system components. Because of the age and unique nature of many APS systems, spare parts may be difficult to obtain, with long procurement lead times, so maintaining a healthy stock of spares is part of the APS strategy for minimizing machine downtime.

7.2 Accelerator Improvements To open new research vistas and meet the expanding needs of current and new users, the APS will improve x-ray beam stability, photon flux and brightness, and the delivery of versatile and stable electron bunch patterns for timing experiments.

Improvement of the x-ray beam pointing stability requires the following:

• Development of a comprehensive set of monitors and correctors coupled by a broadband real-time orbit feedback system to provide the lowest levels of unwanted electron beam motion

• Monitoring of BPM motion using hydrostatic level sensors, invar supports, and capacitive proximity sensors with a micrometer level of precision

• Augmentation of the x-ray BPM systems with grazing incidence x-ray BPMs and Compton x-ray BPMs

• Development of a broadband data acquisition and data processing system to extend up to 1-kHz bandwidth of the real-time orbit feedback system

Improvement in the x-ray flux and brightness require the following actions:

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• Continued development and deployment of revolver undulators capable of delivering x-rays with increased brightness across a larger, more continuous spectral range compared to a single undulator; the prototype revolver undulator was installed in January 2015 at beamline 35-ID

• Continued development and deployment of the planar superconducting undulators for superior photon flux and brightness improvements at high photon energies; installation of the second superconducting undulator is planned for May 2015 at beamline 1-ID

Improvement in electron beam stability and a single-bunch current accumulation limit for timing experiments with high current in a single bunch requires the following actions:

• Continued optimization of the storage ring vacuum chamber components for impedance reduction and deployment of low-impedance vacuum chamber transitions to increase the single-bunch charge

• Continued optimization of the accelerator magnet settings to provide improved lifetime and injection efficiency at high chromaticity, which supports high-charge operation

• Upgrading and enhancement of the transverse feedback systems

7.3 Accelerator R&D to Advance New Concepts and Next-Generation Light Sources The APS has an earned reputation for staying on the cutting edge of accelerator science and technology beneficial for Argonne and other DOE light source facilities. A suite of accelerator R&D programs focused on a versatile, cost effective, and energy efficient future light source ensures that the U.S. and the APS continue to maintain this competitive edge.

The APS core strategy is to perform high-impact accelerator research by concentrating on several areas that maximize key APS strengths: sophisticated, high-fidelity simulation; development of advanced insertion devices; and innovative ideas for improved accelerator performance. While the main path forward focuses on a MBA lattice, opportunities also exist to explore whether the APS can supplement that with additional capabilities for use by specific user groups and for activities beyond the Upgrade path. In these later supplementary areas, the APS will explore long-range R&D ideas for FELs and whether near-term opportunities exist for R&D for using a micro-electromechanical system structure or chirping to produce shorter pulses. Argonne staff at the CNM and the Physics Division will lead the exploration to evaluate the physics case for the use of shorter pulses and whether opportunities for selective use exist in this area. The APS also seeks to take maximum advantage of existing infrastructure to preform R&D at the cutting edge of accelerator physics. The following improvements are under way or planned for the near future:

• Continue development of advanced tools for high-fidelity, thorough simulations that play a critical role in the development of realistic configurations for future light sources; these tools include sophisticated tracking-based optimizations, correction algorithms, simulations of feedback systems, etc.

• Continue development of advanced concepts for future free-electron lasers, including: o Advance basic understanding and develop of novel concepts for FELs, including an x-ray free-

electron laser oscillator (XFELO) and crystal diamond optics used in an XFELO o Advance the concept of a collinear wakefield accelerator suitable for a compact FEL facility

and develop a 1-m-long structure for beam testing o Equip the low-energy undulator test line with a comprehensive set of electron beam

diagnostics, allowing the use of a low-emittance electron beam from the APS linac for characterization of various new diagnostic devices, developing new methods of beam manipulation in phase space as well as characterization of new vacuum chambers and for other beam dynamic studies

• Continue development of advanced concepts for insertion devices, including: o Development of a full-scale prototype superconducting undulator with a superconducting

phase shifter for FEL applications, together with a compact quadruple lens and a high-precision BPM

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o Development of a vertical polarizing undulator with a horizontally adjustable gap and a spring-loaded compensation of the magnetic force; a new 3.4-m-long prototype is under construction now and will be tested in 2015

o Development of helical and bifilar helical undulators capable of fast polarization switching o Development of superconducting undulator technology centered on a unique experimental

cryostat that allows exploration of alternative superconductors, developing error correction techniques, and quickly testing new prototypes

• Continue development and integration of new technologies for 352-MHz rf systems, including: o Development of a high-power modular rf amplifier system utilizing solid-state devices o Development of a fully digital, low-level rf controller for the APS rf systems

• Feasibility studies are continuing on using magnesium diboride (MgB2) and other high-Tc superconducting films suitable for rf cavities; studies are directed toward applying the films to copper cavities with the goal of significantly reducing a cost of a cryogenic plant.

8 Mission Readiness Mission readiness (MR) as defined for the APS facility is the development of a comprehensive plan that anticipates and mitigates risks associated with beamline and accelerator equipment reliability, end-of-life failure, and obsolescence. This approach will be applied to all work that is not included in the scope of the proposed APS Upgrade, but that is required for the long-term, reliable operation of the APS. This plan has many critical interfaces to the proposed APS Upgrade regarding the future configuration, requirements, and schedule for each system. The goal is to deliver:

• An actionable MR plan with defined scope, cost, and schedule

• Justification and prioritization for the necessary resources within the APS operations budget to transparently execute work

Mission readiness for the APS accelerator complex is largely captured in the internal “Accelerator Systems Division Four-Year Development Plan.” A similar plan is being developed for beamlines and the balance of the facility. Details of mission readiness for beamlines and optics support infrastructure is largely captured by the internal X-ray Science Division “Beamline Development Projects Document,” which details maintenance and obsolescence issues for beamlines and optics support over a 5-year timeframe. This document includes both the maintenance and obsolescence projects, and, the strategic upgrades and improvements to increase capabilities listed in Appendix 1, Table 1 (and described earlier in the text). In order to effectively allocate APS funds (both effort and non-effort) and to implement the MR work packages and planning resources in the future, MR will be incorporated into the APS Integrated Management System (AIMS).

9 Infrastructure, General Operations, Support, and Improvements

(Cost-) Effective Operations The APS will pursue top-down and bottom-up mechanisms for assessing the efficiency of APS operations, not only to provide the optimum in user support and mission achievement, but to maximize to the fullest extent the investment by U.S. taxpayers. To achieve this, a concerted effort to assess and improve the APS organization structure will be carried out in order to optimize service delivery across all areas.

The APS is continually looking for ways to improve delivery of core support services through specialized groups working in harmony with customers in the APS accelerator and beamline groups and with centralized Argonne mission support services. To insure that support services are at once responsive to customer needs and carried out in the most cost-effective manner, the APS has employed a work breakdown structure for operations to track effort and integrate this into the AIMS.

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Engineering and Staging Facilities Space available at the APS for instrumentation engineering and staging has been vastly reduced as the experiment hall and lab/office modules have been built out. The APS is working with Argonne mission support to identify possible existing facilities that can fulfill at least some of our requirements, and to develop plans to lease necessary facilities elsewhere if required, for instance for the proposed APS Upgrade.

An Improved APS Experiment Hall The APS requires improved facility environmental controls and vibration levels. APS engineering staff will work with Argonne mission support to define concrete specifications for these parameters and establish integrated plans to achieve the necessary environmental performance.

Network Infrastructure A key aspect for the future success of the APS is provision of reliable, appropriately sized utilities, including Laboratory network infrastructure. Argonne is currently undergoing an infrastructure planning process and the APS has contributed its requirements to this plan.

Helium Recovery System Liquid helium is one of the essential cryogens in the search for new states of matter by enabling access to low temperatures for samples and for cooling superconducting magnets, which are necessary for applying large magnetic fields to a sample. During the past few years, the increased cost and demand for liquid helium has jeopardized the APS ability to operate instruments and conduct experiments that require liquid helium. Therefore, the APS is collaborating with the Argonne CNM to install a facility-wide recovery system, which will capture and re-liquify more than 90% of the helium used at both facilities, leading to full return on investment in ~3 years. This significantly lowers the operational cost for experiments, enabling the APS to continue pushing toward the extremes of sample environments.

10 Human Capital and Workforce Development To ensure that the APS remains at the scientific forefront, management is recruiting, retaining, and developing a highly qualified, high-quality, innovative work force that is diverse and inclusive. The APS is participating in Argonne-level programs and initiatives, and is developing APS-specific programs to target hiring gaps. The APS management also provides staff with mentoring, leadership, and management development and domain-specific professional development opportunities. Of particular interest is the development and support of early career staff, as these individuals are especially vulnerable in a user facility environment and represent the future of the APS mission. The APS utilizes deployed support from the Argonne central human resources organization to perform staff assessments in order to help managers identify staff strengths and weaknesses and opportunities for development. The APS is also developing and maintaining succession plans for key individuals and key functions within the organization. Finally, Argonne has formalized several aspects of its diversity and inclusion program, including the hiring of a Gender Diversity Specialist. The APS is utilizing the Argonne program to foster diversity in its workforce, including execution of annual diversity and inclusion action plans with specific goals and metrics. In the years ahead, these practices will be rigorously applied while other opportunities and methods will be sought to bolster our workforce.

11 User Processes and Scientific Access As noted in the introduction, the APS supports more users than any other DOE facility. The user program at the APS includes an integrated, comprehensive suite of outreach, administrative, support, and educational activities to facilitate quick and easy access to the beamlines and to fill the pipeline of future users and x-ray

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staff. Below are highlighted elements of the user program and delineate enhancements planned for the next five years that will provide even better services to our users.

11.1 Outreach to Users The APS fosters and promotes scientific communication and collaboration through the organization and support of a diverse array of conferences, workshops, schools, and short courses, as well as hands-on training opportunities encompassing the use of x-ray techniques, software, and data collection systems designed to familiarize our users with the ever-evolving technology at the APS and to expand the user base.

• In-house and online lectures that explain the technical parameters of the proposed APS Upgrade assist resident users, particularly CAT resident users, to best align their plans for near- and long-term detectors and optics purchases to maximize the benefits they will derive from the improved source.

• Conferences and workshops focused on diffraction limited light sources, techniques, and science areas in the sweet spot addressed by a MBA source expose current and future users to the capabilities and scientific opportunities of the proposed APS Upgrade. Input from these activities and from other mechanisms is being used to align the selection of upgraded beamlines and accelerator source parameters with user needs and the most transformative science opportunities.

• Conference support for users continues to evolve with the implementation of new tools, such as RegOnline registration software, to improve the registration, access, and payment processes for users.

• A web-based tool developed in-house is shared with resident CAT users to help them choose the optimal undulator system in preparation for the improved source of an upgraded APS.

• With input from our sponsor, users, and staff, the APS website is being refreshed to align with DOE and Argonne websites in terms of design. This has also afforded an opportunity to evaluate the site in terms of functionality and service. The modern web development platform Drupal is being implemented to reduce the amount of effort required for maintaining the site.

• The User Office continues to work with the DOE-SC and with the National User Facility Organization to develop a national database of user statistics and scientific highlights.

In addition, outreach to CAT funding agencies and organizations will help the CATs sustain their operations and implement capital improvements to their facilities.

11.2 User Support/Access The APS provides both administrative and scientific-access support for users. User-related systems are being expanded, streamlined, and integrated resulting in better service for users, better data collection for future planning, and cost savings.

• Recent and ongoing updates of the online registration process are enabling automated data upload from the APS user database to the Argonne foreign national visitor hosting system, thus streamlining requests for foreign visits and assignments for site clearance. This results in significant time savings for both users and User Program staff. Form changes are continuing that focus on accurate “one-stop” data collection to minimize the need for follow-on correspondence. Future plans will further automate the registration/approval process and site access by linking the APS to Laboratory-level systems.

• Planned enhancement of the user check-in tab in the User Portal provides users with a customized summary of documentation requirements for gate access to improve efficiency and ease site access to Argonne and check-in at the APS.

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• “User News” and email correspondence will be utilized to increase user awareness of the toolkit offered in the User Portal, which includes a link to each user’s individual data via the registration system as well as links to systems for online user training, proposal submission, experiment safety approval forms, and end-of-experiment form (EEF).

• Improvements to the EEF system will be made through increased collaboration with beamline staff to expand and improve their use of the EEF, thus capturing user feedback and better gauging user satisfaction and needs.

• The online APS Beam Time Access System is continually updated to meet the changing needs of the user community and expanded APS research capabilities. Improvements to the system will include modifications to better serve the needs of beamline and panel reviewers in supporting their effort to ensure the quality of proposals being awarded beam time.

• Industrial-user requests for access are handled through a special proposal process designed to streamline requests for beam time. The APS is aggressively developing new approaches and outreach programs, such as offering a new guest research agreement to cover the typical one-time measurement access mode.

• A comprehensive review and update of email communications to users generated by the various APS systems is planned. This improves the information pipeline and helps users in many ways — from maintaining site-clearance status, to better preparing for visits and experiments, to sharing important facility and proposed APS Upgrade information, and more.

11.3 User Training Nearly all required user training has migrated to web-based courses that can be taken online before arrival at the APS, saving time and money for our users. The online training course options have been expanded to include access to radiation worker training, a course formerly only available on-site. The APS will pursue online training at the Laboratory level rather than as “mirrored” training on APS servers, which could open new possibilities for tracking training at an integrated human-resource level. Another objective involves looking into “reciprocity” with other national user facilities for training in common core areas such as cyber security. These and other innovations continue to improve the user experience at the facility while keeping APS effort in check.

11.4 Proposal Review Process A credible and transparent user proposal review process is critical to a successful user program. The APS Proposal Review Panels (PRPs) are composed to provide the best possible peer review for beam time proposals, whether organized by technique- or science-driven expertise. The APS uses 10 PRPs to evaluate General User proposals. The number and make-up of the PRPs have evolved, and will continue to evolve in order to best support the changing scientific landscape at the APS. The PRP categories and panel membership are being expanded to address new areas of research at the APS, such as shock physics, which will see a boom in users with the opening of the Dynamic Compression Sector beamline at Sector 35.

Teleconferencing will be integrated as an option for our reviewers in order to save time and travel expenses.

11.5 Training the Future Science Generation APS staff members have been strong and active advocates for training graduate students to more effectively and efficiently use U.S. national x-ray facilities. The APS is continually looking for new avenues to expand networking and education programs, such as the National School on Neutron and X-ray Scattering (NXS), developed by the APS. For the last 15 years, the APS has co-hosted the NXS (originally with the former Intense Pulsed Neutron Source at Argonne, but now in partnership with the Spallation Neutron Source at Oak Ridge National Laboratory). This program has educated approximately 1,000 graduate students. Some

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of the former students are now sending their own students to this summer program. School organizers are expanding the curriculum to train potential users of the next generation of high-brightness sources, such as the proposed APS Upgrade.

More than 40% of the experiments at the APS involve participation by undergraduate or graduate students who are generally part of a larger, university-based research team led by an experienced researcher. This hands-on experience helps students learn to formulate new scientific ideas, prepare successful research proposals, plan and conduct experiments, and analyze and interpret data.

Postdoctoral scholars, often as principal investigators, participate in an additional 22% of APS experiments. It is anticipated that there will be an increase in the number of students using the APS as the capabilities at the facility expand. A strong postdoctoral program at the APS stimulates partnerships with various universities. APS staff members bring postdocs to the facility and seek opportunities to foster x-ray science programs at institutions such as the University of Mississippi that do not (or infrequently) send researchers to the APS.

The APS staff and resident users at the CAT sectors have participated in Argonne’s Exemplary Student Research program (organized by the Argonne educational programs effort) for high school students. Teams of students work closely with an APS beamline staff member to learn about careers in x-ray science and conduct experiments. The APS continues to look for ways to expand this program by leveraging users who have outreach components of their funding.

Staff members also look for opportunities to grow existing partnerships, such as the one with Northwestern University, which carries forward a tradition from NSLS and CHESS at which the current technical leaders at many DOE facilities were trained. Other students and postdocs have leveraged their experience at the APS to run startups, including Xradia, Inc. (currently Carl Zeiss X-ray Microscopy, Inc.), and 2ndLook.

12 Input and Review Mechanisms for the APS 5-Year Facility Plan This “Advanced Photon Source Five-Year Facility Plan” is a baseline guide for large-scale operations spending, user support, and infrastructure/equipment improvements. As this is the first version of the plan, and given the rapid rate of change currently experienced by the APS, an update and revision of the plan will be issued by September 31, 2015. Subsequently, the plan will be reviewed annually and revised on a rolling basis. Updates will also be made as needed to accommodate significant changes in funding, shifts in the priorities of DOE, or new research avenues and opportunities.

Input to this plan was obtained through many channels, including discussions with and/or review by DOE sponsors, the APS user community, sister facilities, resident users, APS staff, Argonne leadership, and the broader scientific community. Review was obtained by direct request for input to this specific document. Discussions (both specific to the document and on a broader basis) occur at regular meetings and reviews (e.g., APS Scientific Advisory Committee, APS User Organization, APS Partner User Council, DOE reviews of APS operations and the proposed Upgrade project, University of Chicago reviews of the APS), regular international meetings and workshops of the synchrotron and general scientific community, and special workshops to consider future strategic plans for the APS and similar facilities.

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Appendix 1: Beamlines and Enabling Technologies

Table 1. Upgrades and Improvements to APS-Operated Beamlines

Beamline Project Completion Funding / Partners

Strategic Areas Priority Improvement Details

1-ID High-energy scattering (SAXS, WAXS, HEDM)

2015 XSD ops/ ARRA, Air Force Research Lab, Nuclear Engineering, Argonne

Engineering materials

High Premier high-energy beamline for engineering materials characterization. Additional end station and detectors (simultaneous SAXS/WAXS and HEDM) to accommodate more complex environments

Unique in situ thermomechanical loading apparatus with in-grip rotation for 3-D tomographic measurements

In-vacuum furnace for irradiated materials.

27-ID Resonant inelastic x-ray scattering beamline

2015 APS-U Emergent materials

High New beamline with enhanced flux and focusing capabilities for studying low-lying electronic excitations

Consolidates programs previously at 9-ID and 30-ID

29-ID Intermediate energy x-ray beamline

2015 DOE, NSF, UIUC, UIC, U of C, IME, NIST

Emergent materials

High New beamline for studying electronic structure in quantum materials using ARPES and RSXS in the 250-2,000-eV range

Pixelated superconducting transition edge sensor detector for RSXS

Legend Project complete – ongoing commissioning

Ongoing near-term projects (complete in ~1-3 years)

Planned near-term projects

Planned long-term projects (complete in ~3-5 years)

Major maintenance and obsolescence

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30-ID High-resolution inelastic x-ray scattering

2015 APS-U Emergent materials

High Optimized undulators provide 2-fold increase in flux

Relocation of RIXS program to 27-ID, fully dedicates 30-ID to HERIX, doubling capacity

32-ID Transmission x-ray microscope upgrade

2015 XSD Ops Emergent materials, catalysis, energy storage

High Full-field transmission x-ray microscope with 30-nm resolution 3-D tomography capabilities and unique large working distance (up to 108 mm) that enables use of sample cells for in situ and in operando measurements

Only dedicated TXM operated by APS

1-ID SCU-1 installation

2015 APS Ops, Argonne

Engineering materials

High Addition of superconducting undulator in 1-ID will increase high-energy brightness by 5x, enabling spatio-temporal studies of the mesoscopic grain structure in materials

3-ID Nuclear resonance scattering beamline

2016 XSD Ops, Argonne

Emergent materials, extreme conditions

High Install fast chopper system and improved focusing optics to eliminate prompt electronic scattering and enable 100x faster data acquisition for time-domain synchrotron Mössbauer spectroscopy

6-ID-D SCU0 upgrade

2016 Argonne, APS Ops

Emergent materials, catalysis, energy storage

High The magnetic core of the prototype SCU0 is lengthened from 0.3 to 1 m providing an ~4x increase in high-energy flux enabling time-resolved (~millisecond) studies of molten liquids

32-ID Full-field imaging beamline

2015 XSD Ops Engineering materials, non-equilibrium

High Install second single-line (~20 keV) undulator for pink beam ultra-fast single-bunch imaging measurements

9-BM Quick XAFS beamline

2016 XSD Ops, EXXON

Catalysis, energy storage, environment, geoscience

Med. Install new quick-scanning monochromator for rapid XAS measurements from 2.1 to 35 keV, accessing the sulfur K-edge

Will enable time-resolved studies of catalytic reactions

17-BM Rapid-acquisition powder diffraction beamline

2016 XSD Ops, Argonne

Emergent materials, catalysis, energy storage

Med. Install new optics to provide higher-energy capabilities (~50 keV) for in situ studies of materials synthesis and catalysis, in operando energy storage

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2-ID Ptychoprobe beamline

2017 XSD Ops, APS Upgrade (proposed)

Emergent materials, catalysis, energy storage, life sciences

High Cant and upgrade 2-ID to provide two independently operating branches optimized for nano-fluorescence and ptychography measurements with sub-10-nm resolution

7-ID Time-resolved pump/probe scattering and spectroscopy

2017 XSD Ops, Argonne Atomic Physics, Argonne

Emergent materials, catalysis, fundamentals of energy conversion

High Enhance optics for improved performance in the 2- to 5-keV energy range and enable pink beam x-ray emission spectroscopy

Incorporate nanodiffraction capabilities coupled to extended pump wavelength range from terahertz to UV

11-ID SCU-2 installation

2017 XSD Ops Catalysis, energy storage, functional materials

High Optimized SCU increases beamline flux by 5x, significantly increasing throughput for in operando/in situ PDF studies for energy storage and catalysis

Many Chemical sciences infrastructure

2016 XSD Ops Energy storage, energy conversion, catalysis

Med. Equip dedicated labs for energy storage and catalysis sample preparation

Install distributed Raman spectrometer system for multimodal studies across chemical sciences beamlines

12-ID SAXS beamline 2017 XSD Ops/ LANL

Catalysis, functional materials, geoscience, life sciences

Med. Install wide band-pass monochromator to increase data collection rates by x100 and enable time-resolved studies

Remain competitive with new beamline worldwide

Apply compound refractive lens optics to small dilute systems

8-ID X-ray photon correlation spectroscopy beamline

2018 XSD Ops, APS Upgrade (proposed), Argonne

Soft Matter, emergent materials, energy storage

High Refurbish optics and install advanced detector systems to enable studies of dynamics at sub-millisecond time-scales

34-ID 2-ID

Enhance nanodiffraction, Bragg - CDI

2018 XSD Ops, APS Upgrade (proposed),

Engineering materials, emergent materials, functional materials

High New experimental station to house combined Bragg CDI (from 34-ID-C) and nanodiffraction from 2-ID-D

Equip with next generation diffractometer for scattering studies with nm resolution

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1-ID High-energy scattering

2019 XSD Ops. Engineering materials

Med. Add additional branch line to double capacity for structural characterization of engineering materials.

11-ID PDF high-energy scattering beamline

2020 XSD Ops Energy storage, catalysis, functional materials

Med. Cant the 11-ID straight section and modify the optics to allow completely independent operation of fixed energy high-energy stations (B, C) and tunable energy station (D)

32-ID Full-field imaging beamline

2019 XSD Ops. Engineering materials, energy storage

Med. Install new optics and detector system for multi-frame imaging at rates up to 6 MHz

Cant beamline for single-shot stereo imaging

2-ID Nano-diffraction

2015 XSD Ops. Engineering materials, functional materials, emergent materials

Retrofit current diffractometer with new nano-positioning sample stages

Replace obsolete motor drivers

4-ID-C Soft x-ray microscopy

2019 XSD Ops. Emergent materials, energy storage

Replace optics to provide 100x increase in flux, enabling the study of more dilute magnetic systems

6-ID-B Resonant diffraction and magnetic-field scattering

2016 XSD Ops. Emergent materials, extreme conditions

Replace optics to provide improved focusing for examining materials under extreme pressure and fields

33-ID Coherent surface scattering beamline

2018 XSD Ops/ Argonne Chemical Sciences & Engineering, Materials Science divisions

Emergent materials, catalysis, energy storage

Replace optics to provide advanced surface characterization facilities that utilize x-ray beam coherence, x-ray reflection interface microscopy, oxide molecular beam epitaxy

Prioritization of beamline upgrade and improvement projects are judged by alignment to the APS strategic plan, which ultimately aims to maximize scientific and societal impact by serving the existing — and attracting new — user communities.

For near-term projects, there are four major considerations: 1) Enhance utilization and capabilities of core strengths of APS that are not duplicated within the DOE light source complex (high energy and timing structure), 2) Enable high-throughput and automation on dedicated single-purpose beamlines, 3) Extend beamline capabilities in conjunction with partner user support, and 4) Off-line laboratory equipment that streamlines or adds multimodal characterization capabilities.

For longer-term projects, the first priority is on beamline projects that prepare for the utilization of new properties of the proposed APS Upgrade, coherence and higher brightness at high x-ray energies, and, second, on increasing capacity for high-energy x-ray techniques.

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Table 2. Upgrades and Improvements in Enabling Technologies for X-ray Science

Group

Project

Completion

Funding / Partners

Priority

Improvement Details

Optics Modular deposition system

2016 XSD Ops., Argonne

High Flexible deposition system with in situ metrology and ion milling for thin-film coating and mirror refurbishment

Optics Hard x-ray zone-plates

Ongoing APS-U, XSD Ops., Argonne

High Develop capabilities for customized zone-plate fabrication with high aspect ratios and stacking for hard x-ray nanofocusing

Optics High-performance diamond crystal R&D

Ongoing XSD Ops. Med. Collaborate with outside institutes to provide high-quality diamond crystal optics for monochromators, beam splitters, windows, and phase retarders

Detectors VIPIC: vertically integrated photon imaging detector

2017 DOE, BNL, FNAL

High Pixel array detector with sparsified readout with on-board auto-correlators for real-time XPCS with µs resolution

Detectors Germanium strip detectors

2016 DOE, BNL High One-dimensional energy dispersive detector array compatible with high energies; this detector will be used for powder diffraction measurements in both energy- and angle-dispersive modes

Detectors High-energy- resolution superconducting detectors

2017 DOE, SLAC, NIST

High Develop high-count-rate, pixelated, energy dispersive detectors with ~1-eV energy resolution for fluorescence imaging with nanoscale resolution

Data collection and analysis

Data storage distribution and analysis

2015 XSD Ops./Argonne MCS

High System for tracking large datasets and managing permissions for off-site retrieval (via Globus Online) placed into workflow at selected high-data-rate beamlines

Data collection and analysis

Tomography workflow and algorithm development

2016 XSD Ops., Argonne

High Development of new streamlined workflows for handling large data sets for rapid tomographic reconstructions (TomoPy)

Data collection and analysis

High-throughput data analysis

Ongoing DOE-ASCR, PNNL, SLAC, LBNL, BNL

High Development of libraries utilizing Swift scripting language for facilitating high-throughput data analysis (PtychoLib and MIDAS)

Legend Ongoing near-term projects (complete in ~1-3 years)

Planned long-term projects (complete in ~3-5 years)

Major maintenance and obsolescence

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Data collection and analysis

Campus-wide shared computing

Ongoing XSD Ops/Argonne MCS

High Through deployment of preemptive scheduling and virtualized computing data analysis, computing integrated with data collection is demonstrated on shared Argonne computers

Data collection and analysis

Generic mail-in automation system

2017 XSD Ops Med. Based upon 11-BM prototype, mail-in workflow is developed and placed into operation for PDF, rapid-diffraction, and ultra-small-angle scattering beamlines and perhaps others

Detectors FASPAX detector 2019 APS-U, Fermilab

High 13-MHz frame rate, high dynamic range, pixelated, gapless, integrating detector

Optics Crystal fabrication 2016 XSD Ops High Procure sub-0.1-degree crystal orientation apparatus, automated crystal polisher for channel cut crystals

Optics Thin-film metrology

2016 XSD Ops High New stitching interferometer with increased stage range for 300 x 300 mm2

and surface roughness to <0.1 Å rms to characterize high-precision mirrors; new Fizeau interferometer for long trace profiler for surface figure measurements on long mirrors

Optics Offline topography

2016 XSD Ops Med. Replace CCD camera for topography and rocking curve imaging

Optics Crystal analyzer fabrication

2016 XSD Ops Med. Fabrication equipment for analyzers with new materials (germanium, quartz, sapphire, lithium niobate)

Optics Ellipsometer 2017 XSD Ops Med. New instrument to measure film uniformity over an extended size range (300-mm)

Detectors Detector Pool On-going XSD Ops High On-going replenishment of aging detectors in the APS Detector Pool for short-term loan to experiments

Data collection and analysis

Data collection refresh

On-going XSD Ops Med. Upgrade beamline controls and data acquisition hardware to enable faster and more automated data acquisition

Projects will be prioritized to maximize the scientific impact of the APS facility with investments in: 1) streamlining operations for data collection and analysis; 2) fabrication of x-ray optics that serve multiple beamlines, with emphasis on R&D utilizing/preserving coherence at high x-ray energies; and 3) development of detectors that use the unique properties of the upgraded APS.

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Appendix 2: User Data

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