GLC Overview

Feb.20, 2004 (rev.4) GLC Overview (N.Toge) - LCPAC 2004 1

GLC Overview

LCPAC 2004 (Feb. 20, 2004)

Nobu Toge, KEK Accelerator Lab.

GLC Overview (N.Toge) - LCPAC 2004 2Feb.20, 2004 (rev.4)

GLC Schematic Layout


Main Linac Unit


Beam Structure 　 vs RF Pulse


X-band Global ParametersCenter-of-mass energy Ecm 500 100 GeV

Pulse rep rate frep 120 (150) 120 (100) Hz

# particles / bunch N 0.75 0.75 x1010

# bunches / pulse nb 192 192

Bunch spacing tb 1.4 1.4 ns

Bunch train length nbtb 0.269 0.269 s

Beam power / beam PB 8.65 11.53 MW

Unloaded gradient ENL 65.2 MV/m

Loaded gradient EL 51.7 MV/m

Total site AC power 241 311 MW

Linac length / beam 7.31 14.21 km

Beam delivery / beam 1.9 1.9 km

Emittance at DR exit x 3.0 x10-6rad m

y 0.02 x10-6rad m

Beam size at IP x* 243 219 nm

3.0 2.1 nm

Peak luminosity L 20.0 (25.0) 30.0 (25.0) 1033cm-2s-1


X-band IP ParametersCenter-of-mass energy ECM 500 1000 GeV

Beam delivery length 1.9 km

Collimation system length 0.7 km

Final focus system length 0.8 km

Full crossing angle 20 (7) mrad

Distance from last quad to IP L* 3.5 m

Pulse repetition rate frep 120 (150) 120 (100) Hz

Bunch length z 110 110 m

Beta function at IP x, / y 8 / 0.11 13 / 0.11 mm

Normalized emittance at IP x* / y* 3.6 / 0.04 3.6 / 0.04 x10-6rad m

Beam size at IP x* / y* 243 / 3.0 219 / 2.1 nm

Disruption parameters Dx / Dy 0.16 / 13.1 0.10 / 10.3

Pinch enhancement factor HD 1.49 1.42

Average beamstrahlung parameter 0.13 0.28

Average energy loss due to beamstrahlung B 4.6 7.5 %

Number of photons per electron n 1.26 1.30

Nominal luminosity L0 14.2 (17.7) 22.2 (18.5) 1033cm-2s-1

Peak luminosity L 20 (25.0) 30 (25.0)


Main Linac Parameters (1)Overall

Center-of-mass energy ECM 500 1000 GeV

Active linac length / linac Einj 8 8 GeV

Total linac length / linac 6.71 13.61 km

Length for linac beam diagnostic and bypass ramps 7.31 14.21 km

Total AC power into modulators / linac 89.0 120.4 MW

Total AC power for RF / linac 98.4 133.1 MW

RF frequency frf 11.424 GHz

Wall plug –to- rf efficiency 32.1 %

RF-to-beam efficiency 29.2 %

Wall-plug-to-beam efficiency 9.37 %

RF unit type 2-pack

Number of RF units / linac 1116 2264

Modulator

Efficiency 80 %

Number of modulators / linac 1164 2264

Klystron

Peak output power 75 MW

Pulse length 1.559 s

Efficiency 55 %

Number of klystrons / linac 2232 4528


Main Linac Parameters (2)Center-of-mass energy Ecm 500 1000 GeV

Pulse Compression

Type Dual-moded SLED-II

Pulse compression ratio 4

Pulse compression efficiency 74.6 %

Phase switching time Tsw 10 ns

Distance between adjacent quads 6.01 m

Accelerator Structure

Type H60VG4S17

Length 0.602 m

Phase advance per cell 150 deg

Iris radius a/ 0.17

Group velocity vg/c 1.8 %

Filling time tf 111 ns

Attenuation parameter T ~ 0.521

Unloaded Q Q ~ 7650

Shunt impedance Rs ~ 70.7 M/ m

RF pulse length 382 ns

Peak RF power per structure 56.0 MW

Average RF phase <> 12.3 deg

Number of structures / linac 8928 18112


Major development in 2003 Efforts on R1 and R2 items as laid out in TRC-II report in collab. with

the NLC team. Part of R1, R2 items cleared – PPM basic validation, SLED-II power

compression. Some remain – Accelerator structures Efforts to continue in 2004 – Acc. structures. “Fuller” demonstration of

SLED-II with additional waveguides and structure loads downstream. Numerous beam control technology R&D at ATF.

Progress made in low-intensity emittance studies (single- vs multi-bunch　 give consistent results at low-intensity)

Steady progress in I&C hardware (e.g. laser wire detector, ODR, XSR) Construction and operation of GLCTA.

A basic 2-klystron power source system was built (~ 60MW, 400ns). Initial system commissioning has begun and is expected to continue in

2004. Will plan extension of the system to include SLED-II pulse compression

or other upgrades in ~2 yrs.


Updated TRC-II Information

http://lcdev.kek.jp/TRCII/TRCupdates.html Status update of R&D efforts related to R1/R2 items

http://www.slac.stanford.edu/xorg/ilc-trc/2002/2002/report/03rephome.htm TRC-II main web site

http://www.ligo.caltech.edu/~donna/ITRP_Home.htm ITRP web site


Quick Dictionary TRC-II （ Technical Review Committee-II ）： Founded

under ICFA in 2001. Charged to review the recent status of LC design schemes and R&D （ SLAC-R-606, published in early 2003) 。 R1 : “R&D needed for feasibility demonstration of the machine” R2 : “R&D needed to finalize design choices and ensure

reliability of the machine” R3 : “R&D needed before starting production of systems and

components” R4 : “R&D desirable for technical or cost optimization”

ILCSC （ International LC Steering Committee ）： Founded under ICFA in late 2002 to act as a steering body for world-wide cooperation on LC development.

ITRP 　（ International Technology Recommendation Panel ）： Placed by ILCSC in early 2003 to recommend on “Technology Selection” for LC


PPM Klystron Status

Specifications [TRC R2#2] : Simultaneous achievement of 75MW, 1.6s, 120 Hz , or higher

Results in 2003: Two PPM tubes built by KEK are approaching the

spec. goals above. A PPM tube built by SLAC cleared the goal in Fall,

2003.


SLAC XP3-375MW, 120Hz, 1.6us operation (511kV, 6% collector

notch, 53% eff, 56dB gain, not saturated)

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A.Vlieks@ISG-11


PPM Klystrons R&D

PPM#2 : under testing at SLAC Klystron lab. Achieved:

- 75MW, 1.7s, 60Hz- 68MW, 1.7s 120Hz

Status:- Gun repair nearly completed.

PPM #4 : under testing at KEK

Achieved:

- 75MW, 1.7s, 50Hz

Status:

- Testing at KEK after window repair has been temporarily concluded as of this week.

PPM #5 : after baking

Status:

- Readied for testing to start at KEK

Y.H.Chin@ISG-11

Y.H.Chin@ISG-11

Y.H.Chin@ISG-11


Plans for PPM Klystrons in 2004

Existing tubes PPM#5 :Has been built in 2003. Test to start at KEK in ~ March. PPM#2 : Repair under way PPM#4 : Temporarily concluded testing in Feb. Some combination of KEK and SLAC PPM klystrons: Long-term

high-rep-rate testing with a 2-pack IGBT modulator at SLAC. New tubes

Further improvements to the body cooling system and electron gun.

More details: see presentation by Y.H.Chin


Accelerator Structure R&D Cells

Test Accelerator Struc.

Most of 60cm-long struc’s tested in 2003 include HOM slots and manifolds as required for GLC/NLC.

J.Wang@ISG-11

T.Higo


Accelerator Structure Summary Specifications [TRC R1#1]: Simultaneous achievement

of 60cm-long ENL = 65MV/m, 400ns pulse length. BD rate 0.1 / 1 hr in 60Hz operation.

Results in 2003: A few strucs cleared the BD goal with ENL = 60MV/m, 400ns. BD rate with ENL = 65MV/m remains x 2 ~ 3 of the goal. Struc-to-struc variation of performance needs to be resolved.

Some are suspected due to known anomalies during manufacturing or vacuum baking.

Much reduced BD rate observed with “ramped” pulse shape, known to be used for beam-loading compensation (All other typical high-power tests are done with rectangular pulses).

Time

Field


High-Power Testing in 2002-2003. H60-series built and tested in 2002-2003.

BD rate found to be prop. to gradient.

“Acceptable” BD rate performance at 60MV/m.

Performance not YET acceptable at 65MV/m. With pulse “ramping” substantial improvement seen.

Struc-to-struc variation of permance needs to be resolved. Keep eyes on manufacturing / heat processing.

Must accelerate the data collection with a plural # of structures with identical design and build.

C.Adolphsen, Jan.2004


Plans for Acc Structures in 2004 Highest priority: Additional construction of H60VG4S17-type structures

Improve the statistical / systematic confidence in performance observations of the latest struc design.

At SLAC expect to exploit the 2-moded SLED-II power source, in addition to the existing NLCTA test stations for accelerated, parallel testing.

Later this year we may reconsider - More improvements to the structure design, or GLC/NLC overall parameter optimization (ENL : 65 60MV/m gives only minor

impacts on the cost, no impacts on the luminosity ） In parallel, try to improve the domestic capabilities ：

More purely-made-in-Japan structures. Build up infrastructure at GLCTA.

More details: see presentation by Toshi Higo


Pulse Compression (2-moded SLED-II) Summary

Specifications [TRC R1#2] ： simultaneous achievement of producing X-band RF power of 475MW, 400ns

Results in 2003 ： Test at SLAC produced 475MW, 400ns at 30Hz on

12/4/2003. Continual operation for 100 hrs. Used solenoid-focussing type klystrons x 4 as power source.

Maximum: 580MW, 400ns.


56MW

Tested in 2003Used solenoid-type klystrons x 4


Input and Output pulses with SLED-II

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Time (s)Sami Tantawi (1/27/2004)


Plans for SLED-II in 2004

Distribution of the SLED-II power to accelerator structures Phase 1: 4 structures in Spring, 2004. Phase 2: 4 more struc (8 in total) in Summer/Fall, 2004. At each phase, semi-long-term operation at 60Hz. Integration with structure testing in ~ Summer. Integration with PPM klystrons later as found possible.

KEK team will contribute Hybrids (overheight models) to use as “power splitters” Personnel to participate in test operation at SLAC

More details: see presentation by Y.H.Chin


56MW

2004 Expansion of SLED-II testing

Phase 1

Phase 2 addition

Switching to PPM tubes as found possible

Introduce newly-built acc strucs as found available


SLED-II additions in 2004

D.Schultz @ISG-11


GLCTA Set up next to ATF.

Possible beam acceleration exercise in the future.

2 solenoid-focused klystrons, straight power combiner, feeding one acc struc, as starter. Initial set-up built in 2003. Aim at testing ~ 65MV/m in 60cm-

long structures in 2004. Later implement PPM klystrons. SLED-II also.

Considering GLCTA as a homeground for building up domestic infrastructure / human resources. Continue full collaboration at

NLCTA concerning rapid validation of required X-band technologies.

For more details: see presentation by H.Hayano and T.Higo. H.Hayano@ISG-11


GLCTA Hardware as of 2003

H.Hayano@ISG-11


Plans for GLCTA in 2004

Stable delivery of 60MW, 400ns power to one 60cm-long accelerator structure Powered by a pair of solenoid-focussed klystrons. Misc improvement program in WR90 waveguide system. Possibility of introducing circular WG for power handling margins. Establish an acc struc test station similar to NLCTA..

Preparation of RF power compression HW New, PFN-based “two-pack” modulator delivery expected in Feb. Commission the two PPM-focussed klystrons delivered in 2003. Misc design and prep work for the pulse compressor hardware

More details: see presentation by H. Hayano, T. Higo, Y.H.Chin


Summary System Validation R&D for X-band (Higo / Chin)

Acc Struc: Clarify the high-power performance at around 60 – 65 MV/m in 2004. PPM Klystron: Successful operation done in 2003. Will continue long-term +

high-rep rate operation exercises in 2004. SLED-II: Successful production of 475MW, 400ns pulses done in 2003. Will

implement a full set of waveguide systems and acc structures downstream; and conduct a long-term operation exercise in 2004.

ATF (Hayano) Beam physics:

Consistent emittance results in low-intensity single-bunch vs multi-bunch operations in 2003. Need to check high-intensity performance in 2004..

Performance when wigglers are turned on. Study scheduled in 2004. Beam instrumentation: Progress seen in understanding of laser-wire “thickness”,

ODR, OTR, XSR. Continue efforts in 2004. FEATHER: Fast beam feedback control exercise with nm-resolution BPMs. Prep

efforts initiated in 2003, to continue in 2004. Also in Japan

Modulator: Test operation of IGBT-type model scheduled in Spring-Summer, 2004 (Chin).

GLCTA: (Higo, Hayano) Built in 2003. Will set up the system so that high-power operation of one 60cm-long acc

struc becomes a routine in 2004. Towards 2005, prepare implementation of SLED-II, with PPM tubes.

C-band (H.Matsumoto) High-power test of acc struc: Scheduled at SPring-8 in spring, plus related

development

Documents

GLC Overview