2010-3-28 1

SRF GroupInstitute of Heavy Ion Physics, Peking University

ILC GDE Meeting 2010/26/03, Beingjing

Efforts on the R&D of SRF cavity at Peking University

2010-3-28 2

Ø Cavities made by Peking University

Ø Development of relative techniques

Ø Future plan

Contents

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Cavities made by Peking University

Efforts on the R&D of SRF cavity at Peking University

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1988 1994

2000

2006

2005大晶粒铌大晶粒铌大晶粒铌大晶粒铌材超导腔材超导腔材超导腔材超导腔2004

2002

2009

20082007

SRF group

2×9cell

2×3.5cellDevelopment of SRF at PKU

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L-G Nb Cavities made by Peking University

Collaboration with OTIC to develop Large Grain Nb cavity since 2005

ØSimplify the machine process of Nb sheetsØOnly BCP is needed

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In 2006, acceleration gradient of 1.3GHz Large grain single cell reached 43.5MV/m, Bp=185mT PKU Large Grain cavity

after post-purification at 1250C

1.0E+09

1.0E+10

1.0E+11

0 10 20 30 40 50

Eacc[MV/m]

Qo

Test #5a, a fter 1250C+bakingTest#1BCP+baked, before 1250C

Quench

L-G Nb Cavities made by Peking University

After BCP treatment & baking at 1200C for 12 hrs by Dr. P. Kneisel at J-Lab

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In 2007, large grain 2-cell cavity , 40 MV/m

L-G Nb Cavities made by Peking University

Vertical test at DESYAfter 80 µµµµm BCP, HT 8000C, 100 µµµµm EP, 4 x HPR, HT 1200C in Ar atmosphere, kept at 90-140 K for 24 hours

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In 2009，3.5cell large grain cavity, 23.5MV/mL-G Nb Cavities made by Peking University

Vetical test at JLab

Large grain 3.5 cell Nb cavity of 23.5 MV/m @ Q0 >1E10 after BCP, HPR and HT 2 hrs at 8000c by Dr. R. Geng at J-Lab

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no quench

In 2008, first 9-cell cavity in China，，，，Eacc is 23MV/mF-G Nb Cavities made by Peking University

Vertical test at JLab

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F-G Nb Cavities made by Peking University

Fine grain Nb cavity

Treated & Tested by Dr. P Kneisel at JLab

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10 Cavities totally10 Cavities totally10 Cavities totally10 Cavities totally，，，，6666 with end groupwith end groupwith end groupwith end group

3 single cell，，，，2 2-Cell，，，，1 5-Cell，，，，2 3.5-Cell，，，，3-9Cell

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Development of Relative Techniques for Cavity

Recent Progresses of SRF Technology at Peking UniversityRecent Progresses of SRF Technology at Peking UniversityRecent Progresses of SRF Technology at Peking UniversityRecent Progresses of SRF Technology at Peking University

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Development of Relative Techniques for Cavity

Deep drawing and machining of cups

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Development of Relative Techniques for Cavity

EBW studies: collaboration between HIT (Harbin Institute of Technology) and PKU

266×1.7(mm)

1 EBW machine

2 sample welding

3 dumbbell welding

4 cavity welding

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Development of Relative Techniques for Cavity

RF test and tuning of cups and dumb–bells

Measure the frequency and coupling factor (k) for the dumb-bell

Measure the frequency of cups

Geometrical test

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Development of Relative Techniques for Cavity

Defect detection

Cleaning

Anode oxidizing

BCP Polishing

Processing of Nb dumbbells

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Development of Relative Techniques for Cavity

Annealing at 1250°C in Nb box with Ti plate & rod at

Ningxia OITC

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Development of Relative Techniques for Cavity

Tuning for 9-cell cavity

SRF cavity tuning facility

Before Tuning

110.00

110.50

111.00

111.50

112.00

112.50

113.00

113.50

114.00

0.00E+00 5.00E+00 1.00E+01 1.50E+01 2.00E+01 2.50E+01 3.00E+01 3.50E+01 4.00E+01 4.50E+01

Time(s)

Deg

rees

`

After Tuning

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Development of Relative Techniques for Cavity

HOM coupler

Fundamental mode

HOM coupler test results

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Recent Progresses of SRF Technology at Peking UniversityRecent Progresses of SRF Technology at Peking UniversityRecent Progresses of SRF Technology at Peking UniversityRecent Progresses of SRF Technology at Peking UniversityFuture Plan

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DC-SC photocathode injector

3+1/2 cell cavity is installed in DC-SC photoinjector

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DC-SC photocathode injector

Cryostat of 3.5cell DC-SC photoinjector

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Cryo-modules

LHe输液管 预冷管 He回气管LHe储存罐液面计 9－cell 超导腔超导腔液氦槽 两相管 LN 管道及LN 冷屏恒温器真空容器 LN 储存罐

主耦合器悬挂结构调谐器水平拉杆 真空泵接口 门阀测温电阻 超导腔内部支撑LN 屏支撑

9-cell cavity is installed in a Cryo-mudule

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Cryo-modules

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Future Plan

ØBCP system for 9-cell cavity and vertical test system will be built

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Future Plan

A “well” with 5m depth and 1.3m diameter is ready

acceleratorinjector

2K

undulator

RF power laser

Cryogenic system

Test cave

Clean roomCooling water system

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Future Plan

First 2K cryogenic system for SRF in China

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Future plan

More 9-cell cavities will be fabricated with higher Eacc!

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Thank you!

Recent Progresses of SRF Technology at Peking University

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lBCP， ~ 100 µm

l600°C ， 10 hrs

lField flatness tuning

lBCP，~50 µm

lHPR，~ 5 hrs

lBCP，~50 µm

Pretest processing of 9-cell cavity

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30840[Ω*Ω]R/Q*G

271[Ω]G

113.8[Ω]R/Q

4.15[mT/(MV/m)]Bpeak/Eacc

1.98-Epeak/Eacc

1.9[%]kcc

35[mm]riris

37970

284

133.7

3.61

2.36

1.52

30

35123

277

126.8

3.76

2.21

1.8

33

TTF LL RE

1992 2002/2004 2002

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Efforts on the R&D of SRF cavity at Peking University

Heat load (at 2K)

Pulsed CWStatic heat load of main accelerator 12 W 12 WDynamic heat load of main accelerator 4.4 W 88 WStatic heat load of injector 6 W 6 WDynamic heat load of injector 1 W 20 WTransfer lines 10 W 10 WTotal heat load without contingency 33.4 W 136 WTotal static heat load with 50% contingency

42 W 42 W

Total heat load with 50% contingency 50.1 W 204 W (150L/h)

DutyFactorQRQ

VPdiss ×

⋅=

/0

2