TTC Meeting Frascati Dec 5-7 Bernd Petersen WG3: Module Test-Stand Summary Charge of the working...

TTC Meeting Frascati Dec 5-7

Bernd Petersen

WG3: Module Test-StandSummary

Charge of the working group:

Define scope of module test-stand activities with and without beam

Conveners: Hitoshi Hayano, Shekhar Mishra, Bernd Petersen,


Bernd Petersen

We had 6 talks:

• Test program on the CMTB/CMTF at DESY (Yury Bozhko, DESY)

(test without beam)• Status and plans for the ILC-module design (Tom Peterson,FNAL)

(object which needs tests)• HOM measurements at the TTF (Marc Ross, SLAC))

(very important tests with beam)• Beam measurements at TTF (Hans Weise,DESY)

(another examples for very important tests with beam)• Status of ILCTA at FNAL (Sergei Nagaitsev, FNAL))

(plans for tests with and without beam)• Planned beam measurements at STF (Hitoshi Hayano, KEK)

(test with beam in two phases)


Bernd Petersen

In this summary I will concentrate on the test stand issues

(several other detailed aspects were discussed by the experts)


Bernd Petersen

Status and plans for the ILC cryomodule design

Tom Peterson, Fermilab

TESLA Technology Collaboration Meeting

Frascati, 6 December 2005


Bernd Petersen

TTF cryomodule is our reference


Bernd Petersen

Type IV cryomodule will differ from type III+ in the following general

areas• Cavity iris-to-iris spacing reduced to 283 mm

– Reduces length from 12.20 to about 11.8 m, get ~0.75 packing

• Slow tuner modified to allow closer cavity-to-cavity spacing (could mean switching to blade tuner design, but choice still open)

• Fast tuner -- new design • Quad/corrector/BPM package under center post, hung

from 300 mm tube, not on rollers (diverging from X-FEL) – Two major module types, one with quad and one without


Bernd Petersen

More differences of Type IV cryomodule from type III+

• Interconnect features modified to accommodate input coupler at end of cryostat

• Quad current leads may be new and different, with local impact on thermal shields and vacuum vessel ports

• Provisions for quad power lead connection at center of module

• Some pipe sizes will be increased for lower pressure drops with high flow rates -- would like to retain long cryogenic unit lengths up to limit of 300 mm pipe and cryo plants. Present effort includes re-analysis of heat loads, flow rates, and cryogenic system thermal process.


Bernd Petersen

(Increasediameter beyond X-FEL)

(Increasediameter beyond X-FEL)

(Review 2-phase pipe size and effect of slope)


Bernd Petersen

Some critical open design issues

• Quad/corrector/BPM package is a major unknown right now and goes into the heart of the module

• Tuner details, slow and fast, but especially fast tuner • Vibrational analysis, which will be compared to

measurements for verification of the model for future design work

• Development of module and module component test plans

• Verification of cavity positional stability with thermal cycles• Design of test instrumentation for the module • Robustness for shipping, analysis of shipping restraints

and loads, shipping specifications

• Active quad movers(?) A complication


Bernd Petersen

Type IV probable schedule• Design module -- 12 - 24 months (2006 -

2007) – Magnet/BPM package – Tuners, etc. – Integrate into module design

• Build and test -- 12 - 18 months (2007 - 2008) – In addition to module, need module test stand and

test facility!

• Total 2 to 3 1/2 years, depending on scope of work and availability of resources.


Bernd Petersen

Type IV is not the (final) ILC design• Test results of types III and IV will teach us

a lot • There will be some choices beyond type

IV from parallel development efforts • Industrialization will have a significant

impact on the design • Type IV is the next step in module design

for ILC


Bernd Petersen

Discussions:

• Keep the components exchangeable for the different test facilities ! ( He pipes will stay in the present positions )

• Quad for ILC is not yet defined

• All design changes will require the related tests


Bernd Petersen

Proposals to the test programto be carried out at DESY on the

Cryomodule Test Bench

and

Cryomodule Test Facility

Yury Bozhko DESY


Bernd Petersen

Cryomodule Test Bench (CMTB)

Objectives: on the test bench complete system-tests of cryomodules have to be conducted aiming to finalize design of the XFEL–cryomodules and the related sub-systemsPlanning:• the Test Bench will be commissioned in April 2006• first modules to be tested are either the Superstructure as a dummy in May or the Module 6 in June 2006


Bernd Petersen

Cryomodule Test Facility (CMTF)Objectives: • testing all main components constituting the cryomodules as cavities and superconducting magnets • qualifying all cryomodules after the assembly Planning:• beginning of the construction - 2007• installation of the cryo- and RF equipment – middle of 2008• commissioning – middle of 2009

Modules' storage area

Storage area magnets and cavities

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Cryo-distribution

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CryoModule Test Stands

CryoCavity tests

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Non crane accessible area

CMTF includes:

• three cryomodule test stands• two vertical bath cryostats for testing single cavities• one horizontal bath cryostat for testing SC magnets• one horizontal cryostat for testing assembled cavities


Bernd Petersen

CMTB and CMTF: Common program for the cryomodules‘standard’ test program without beam

• Mechanical check of components: alignment of beam tube, cryogenic tubes, coupler and vacuum flanges, feedthroughs etc., have to be checked.

• Leak tests of the vacuum systems (beam pipe, coupler and insulation vacuum) and cryo-pipes under He pressure

• Conditioning of the main RF-couplers (cavities off resonance)

• Conditioning with resonant cavities (check of tuning systems)

• Measurement of the dynamic cryogenic loads of the cavities to get the Q versus Eacc characteristics of the cavities and their maximum acceleration fields.

• Tests of the current leads of the SC magnet

• Static cryogenic heat loads will be measured at 40/80, 4.5 and 2K

• Monitoring of dark currents at one end of the beam tube of the cryomodules at both ends !


Bernd Petersen

CMTB specific tests: Displacement and vibrations measurements

Displacements of the cold mass during and after cool down/warm up will be measured with the help of Wire Position Monitor system

Prototype cryostats and the related systems will be extensively thermally cycled to investigate the influence on the performance of the modules.

Novel generation of fast WPM electronics (INFN) would allow vibrations measurements

CMTB specific tests: Thermal cycling

CMTB specific tests: HPP processing

Depending on the performance of the cavities in the module in comparison to the original tests results during the vertical tests of the individual cavities and depending on the onset of field emission, the cavities will be treated by HPP procedures.


Bernd Petersen

CMTB/CMTB tests (cond.)

• Special tests on CMTB: inclination, T-variations, venting….

• Test program for sc magnets at CMTF

• Single cavity tests at CMTF


Bernd Petersen

CMTB/CMTF discussions

• Quad will only be tested at 4.5 K

• Main Couplers will be completely pre-conditioned before assembly to the module

• Standard test program was not questioned

• Dark current measurements are an issue !


Bernd Petersen

Preliminary results from TTF HOM BPM system

TTC meeting, December 6, 2005

Marc Ross (SLAC) for

Nicoleta Baboi, Rita Paparella, Olivier Napoly, Claire Simon, Joe Frisch, Tonee Smith, Justin May,

Doug McCormick, Linda Hendrickson

(DESY, Saclay, SLAC)

and the TTF team.


Bernd Petersen

TTF HOM BPM system

• Purpose: – Find centers of cavities wrt each other

• Minimizing HOM power should improve beam dynamics (ACC1)

– Augment existing BPM system; prove/disprove viability of HOM usage for BPM


Bernd Petersen

Signal– Dipole HOM phase and amplitude depends on

offset and angle • Alternatively ‘sine-like’ and ‘cosine-like’ trajectory

distortion amplitudes, depending on phase definition..

– Basically ‘transit time’ effect– May find other distortions, but no evidence to date

– Concern about damage caused by possible high power – installed additional 10dB attenuators.

• Should worsen resolution 3x


Bernd Petersen

Dipole Mode Response to Beam

Note that centers (position / angle for zero signal) of HOM modes are modified by asymmetric couplers at the ~100 micron level

Beam position offset produces m ode am plitude proportional to (position) X (charge)

Beam at angle produces signal at start ofstructure, cancels at end of structure:Result is “derivative” like signal, 90 degreesout of phase with position signal

Am plitude is proportional to(Angle) X (charge) X (cavity length)

Bunch tilt signal produces a signal with the sam e phase as the beam angle signal

Am plitude is proportional to (Tilt) X (charge) X (bunch length)

Not significant for the DESY TTF(bunches are very short)


Bernd Petersen

Minimum power location – x – rms 420 um


Bernd Petersen

Minimum power location – y – rms 467 um


Bernd Petersen


Bernd Petersen

Discussion

• HOM measurements will have to be continued for ACC4,5,6 and will be directly compared to WPM measurements

• Preliminary results acceptable for XFEL but not for the ILC

• This kind of HOM BPM measurements will be integrated in the ILCTA and STF facilities ( + WPMs)


Bernd Petersen

The Advantage of Having Beam at a Module Test Stand

Hans Weise, DESY

Working Group 3TESLA Technology Collaboration Meeting

Frascati, December 5th - 7th, 2005


Bernd Petersen

Advantages of having a beam on a module test stand

• Gradient check (RF measurement has +/-10 % error)

• Effects of beam loading-> LLRF studies

• HOM excitation

• Check cavity alignment with beam HOM BPM method

• Precise measurement of dark current (use of spectrometer ?)


Bernd Petersen

Status of ILCTA@ Fermilab and plans for beam tests

Sergei Nagaitsev

Fermilab


Bernd Petersen

ILC Research and Development at FermilabTwo main branches:

Develop world class SCRF expertise: module fabrication facility + module test facility

“Reference Design Report effort”: machine design and site studies


Bernd Petersen

Beam test plansNew Muon Lab – need a new name! FNPL Photo-injector

Building a dedicated ILC cryomodule test in the New Muon Lab – Cleaning out building (Done) except for CCM– Plan is to install interim cryogenic solution in FY06– Move FNPL Photo-injector to provide electron beam (Late FY06)


Bernd Petersen

•Need to test things as far as possible in a realistic situation need beam!

•Cavity gradient, gradient spread, dark current, cryogenic load, radiations levels with beam operation Measure acc. gradient by measuring beam energy

•Evaluate performance of LLRF system: e.g. R&D on new algorithms; demonstrate 0.1% bunch-to-bunch energy spread over ~1 ms train

•HOM studies, including trapped modes;

Reasons for beam tests (from SMTF meeting)


Bernd Petersen

Reasons for beam tests

• Beam-based measurement of component alignment and vibrations

• Possibly (?) measure single bunch wake-field effect in cryomodules

• Measure beam kicks due to couplers, cavity tilt, quad rotations + tilt errors characterize focusing properties of SCRF cavities


Bernd Petersen

Beam plan at STF phase1

12/6/2005 TTC-WG3 H. Hayano

STF phase1 1st step : DC-gun + photo-cathode (2006)　　　　 quick beam source( DC gun exist), no pre-acceleration, no buncher, but high density beam -> big space charge, bad transmission.

2nd step : RF-gun + photo-cathode (2007)　　　　 similar to TTF, but heavy-load of laser development* RF-gun: easy extension of S-band RF-gun of ATF.

*Laser development will be done continuously from step 1 to step 2.

** Why two step?: limited budget and man power, however need some beam to confirm cavity gradient in initial stage.


Bernd Petersen

Reason of Beam at STF

To develop following performance & technologies;

1. Cavity gradient, 2. LLRF control for beam loaded cavities,

3. HOM studies for TESLA type and LL type, 4. Instrumentation (BPM, BSM) development,

5. Laser development for ILC beam generation, later, want to expand them to ILC Pol e- generation study*. (* Pol e- : by Nagoya-univ. and KEK collaboration)


Bernd Petersen

Define scope of module test-stand activities with and without beam

Activities without beam

• Mechanical checks,RF,vacuum,cryo performance tests,dark-currents, special cryo-tests

Activities with beam

• Gradient checks,beam loading LLRF, HOM BPM,dark-currents, cryo-loads, development of instrumentation

TTC Meeting Frascati Dec 5-7 Bernd Petersen WG3: Module Test-Stand Summary Charge of the working...

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