RF & Linac DesignAccelerator DesignProgram Update

Chris Adolphsen

Department Programs• International Linear Collider (ILC)

– All ILC areas except for ATF2 (APE and Test Facilities)• FNAL Project X

– L-band CW (650 MHz) and Pulse rf (1.3 GHz) sources, …• LARP

– Rotatable Collimator– UA9 Crystal Collimation– …

• SuperB– IR Design– Ring RF– ….

• X-band– CLIC Structure Tests– X-band Gun Development– X-band Linac Driven Light Sources (MEGa-ray, MaRIE, …)– ….

• Support for FACET, LCLS, Controls Upgrade, …

Klystron Cluster Scheme TestsResonantly power a 0.5 m diameter, pressurized (1 atm N2), 10 m long aluminum pipe to 300 MW TE01 mode field equivalent in 1 ms pulses

Time of Position 2 markers (T1,T2) are ~ 1 ms later than those from Position 1, which suggest events are much closer to Position 1 (5 m / 5100 m/s ~ 1 ms) T1 T2

Acoustic Sensor Breakdown Localization

CTO 21

0 10 20 30 40 50 60 70 800

200

400

600

Time: HrsP

ower

to C

TO (k

W)

0 10 20 30 40 50 60 70 8070

71

72

73

74

75

Time: Hrs

dBm

550 KW input power yields 300 MW equivalent surface fields in the pipe - see bkd every ~ 15 hours, maybe from CTO or upstream – rate seems very pressure dependent

‘Big Pipe’ Operation

Next: 160 m Resonate Ring

Status of ILC e- Source Laser System Development

• Two similar laser systems are being developed:1. SLAC design2. SBIR laser system (KM Labs)

• Both systems share similar challenges– CW amplifier pump lasers

• KM Labs system has been operational at 1.5 MHz at KM Labs facility inspected in October 2010

• Delivery in December 2010• KM Labs and SLAC systems are now in the process of installation

at SLAC’s ILC ITF• After KM lasers running at 1.5 MHz, will do a gun test and then

augment the PI pumps with the Coherent lasers to bring the KM system up to 3 MHz

KM Labs System Installation

Top Left: JohnS at KM Labs in Boulder, CO in OctoberTop Right: the laser being brought into B006 in December

Bottom: the laser on the table in Rm 107, B006 wherein we have tested the Photonics Industries (PI) green pump lasers. One of these work, one of these has low output.

Gun Development at JLab

Inverted InsulatorCathode

Anode

NEGs and Ground Screen

AnodeFeedthrough

JLab's Inverted gun design

Conditioned to 150kV without observed field emission

ILC DR Electron Cloud Working Group Tasks & Status

Reduced DR Circumference – ILC Low Power Scenario

Evaluation of reducing the DR circumference to one-half that specified for the RDRCorresponding reduction in bunch count to one-half of the RDR specification

Baseline Mitigation Recommendation

Evaluation of EC Mitigation R&D ResultsIdentify the most promising mitigation schemes

Identify candidates and issues for further R&D

Restored Bunch Count

Evaluation of options to restore the RDR bunch count for high luminosity operationIdentify safe path to restore bunch countEvaluate performance limits in low power configuration

March 2010October 2010

Under Evaluation

Participating Institutions:ANL, Cornell, INFN, KEK, LBNL, SLAC

Working Group coordinated by SLAC (M.Pivi).

Electron Cloud Mitigation Options

10

Clearing ElectrodesKEKB

Grooves w/TiN coating

Clearing ElectrodeCESRTA

Grooves on CuAfter extended operation

Stable Structures

Reliable Feedthroughs

Manufacturing Techniques& Quality

LanfaQuadrupole Region Evaluation for the 3.2km

DR for Possible High Current Operation

Need SEY~1 or better in quadrupoles with short bunch spacingsNeed to understand antechamber role CLOUDLAND simulations

(L.Wang, SLAC)

ECLOUD10 Workshop

MDI Work in Progress

Hall Design, Detector & Platform Vibration Analysis, “R20” Package w/ QD0 mover system, Frequency Scanning Interferometry Alignment

First Simulations of a Network of Launch Points and Retroreflectors for QD0K. Riles – U. Michigan

Vibration Measurement System to Support ILC MDI R&D: Testing on the SLD Detector

• Andrei Seryi’s old vibration measurement system has been resuscitated• Custom battery-operated preamps have been built• System noise level is very low: ~0.25 nm RMS (integrated power > 1 Hz)

SLAC Rotatable Collimator for LHC

Ratchet Gear Drive

RC-0 Jaw (copper)

RC-1 Jaw (Glidcop)

LHC IR7 Style BPM Buttons4 per end

Flex Support

Tank geometry allows a 60mm facet-to-facet gap in fully retracted Jaw position

Ferrite couldmount to BasePlate facing Jawfacet

BPM assemblies at each end are fiducialized to Collimator

Base Plate

Drive Mechanism

RF foils carry image current and shields Rot. Mech.

StatusIn Q1 FY11, mechanical work included the rebuild of the RF rotation mechanism on one of the jaws and the final reassembly/rebuild of the drives with W-S2 coated bearings.

The new design was tested to x5 anticipated torque required for rotation.

The four bellows were vacuum fired and welded on. Leak checking showed 9-scale vacuum.

Current Near Term R&D Plan• Ship first rotatable collimator prototype to CERN ASAP• Mechanical, vacuum & impedance tests by CERN personnel• Installation in SPS during technical stop of LHC

Location identified

• Beam tests of prototype in SPS in early 2011 Impedance

Operation

• Robustness tests in HiRadMat Facility ~ Summer 2011:

1 MJoule per accidental beam-abort Test extent of damage: molten & gaseous debris, hit face, adjacent face..

Permanent shock induced deformation of jaw

Operation of rotation drive & integrity of water circuits after impact(s)

SuperB Interaction Region

0

100

200

-100

-2000 1 2 3-1-2-3

mm

cm 3-Oct-09 M. Sullivan SB_I_ILC_R3_SR_3M

QF1QF1

HERLER

PM

Solenoids

QD0

300 mrad

Cryostat m

Developed a scheme for solenoid compensation that involves rotating the PMs as well as cancelling the detector field as much as possible

Recently, an orbit and skew correction scheme was developed to enable the machine to run with the detector field off using the same compensation hardware

Non-RF Bunch Linearizer for a All-X-Band Linac

Yipeng Sun

Simulations for 250 pC BunchesBC1:over-compress BC2:under-compress

Yipeng Sun

Use of Truncated Gaussian Laser Profile to Reduce LCLS Emittance

• Can improve LCLS projected and slice emittance 20%+• It is supported by theoretical analysis - space charge

forces are more linear in the Gaussian-cut case.• Scheduled to LCLS beam verification in late February.

x/r=0.5

x/r=1.0

x/r=10

F. Zhou, P. Emma, and Z. Huang