1.3 GHz SRF Cavity R&D Plan

Jiyuan Zhai

ILC Group, IHEP

3rd IHEP-KEK 1.3 GHz SRF Meeting, 7 Dec 2010, Beijing

Outline

• 2011 Plan

– IHEP-01 (LG LL 9-cell w/o HOM) 2nd VT

– IHEP-02 (LG LL 9-cell w/ HOM) fab, VT and dressing

– IHEP-03 (FG TESLA 9-cell w/ HOM) fab and VT

• 2012 and after

– IHEP-02 horizontal test

– ERL (7-cell and 2-cell), 2011-2015

– ADS (beta 0.8, 1.3 GHz 9-cell cavity) , 2012-2015

CW, High Current

IHEP-01 large grain 9-cell cavity

• Fabrication: 2009.2 – 2010.4

• Processing: 2010.4 -5

• 1st VT: 2010.6-7– vacuum 2~5E-7 Pa

– T-mapping, no X-ray mapping

– Kyoto camera inspection

– replica

• 20 MV/m (cell #9, #2 quench)– defects not exactly identified

• Field emission– CP stains or iris defects 0 5 10 15 20 25108

109

1010

1011

Qo Pi mode [4 K] Qo Pi mode initial [1.76 - 1.73 K] Qo Pi mode final [1.88 - 2.02 K]

Eacc, max = 8.4 MV / m

Qo = 3.95 * 108

Po = 164 W

CBP (190 μm), BCP (110 μm), Annealing (750oC, 3 h), Pretuning (94 %), Ultrasonic

(Micro-90 2%, 50oC, 3 h), BCP (20 μm), Ultrasonic (UPW), Low Pressure Rinsing @ IHEP

Ultrasonic (Liquinox 2%, 43oC, 3 h), HPR (8.5 h), Baking (105oC, 48 h), VT @ KEK

Final: Quench (self pulse) / F.E.Eacc, max = 19.8 MV / m

Qt = 1.40 * 1012

Qo = 1.57 * 109

Po = 230 WHe pres. = 2.69 kPaHe temp. = 1.94 K

Initial: F.E.Eacc, max = 6.3 MV / m

Qt = 1.46 * 1012

Qo = 1.66 * 109

Po= 21.9 WHe pres. = 1.36 kPaHe temp. = 1.73 K

1st Vertical Test, July 1, 2010

IHEP-01 Large Grain Low Loss 9-cell Cavity (without HOM couplers)

Q0

Eacc

[MV/m]

IHEP-01 defects and reprocessing

Quench defects

• X-ray photo (cell #9 slot)

• Local grinding (cell #9)

• CBP

Field emitters

• CP stains – 2nd CP attention

• Iris defects – no way to remove, maybe not matter

#2, 340°33 MV/m

#4, 156°> 25 MV/m

#9, 270°, 20 MV / m1

mm

#3, 85°> 21 MV/m

equator

1 m

m

IHEP-01 2nd processing and VT schedule

Task [preparation] Time (days) Notes

Local grind [new inspect tool, X-ray photo] Dec.12-17 (5) Totally 30 days

CBP (100 μm) [jig, stone, maintain] Dec. 20-28 (7) Visa document

LPR, ultrasonic Dec. 29-30 (2)

1st CP (100 μm) and outside CP [acid] Jan. 7 (1)

HPR (1 hour) [jig?, test, avoid damage!] Jan. 7-8 (2) Then 10 spare days

Annealing (Ningxia or Beijing) Jan. 17 -21 (5)

Pretuning (vertical) , jig modify & fitting Jan. 24-28 (5) Holiday 1.29 – 2.9

2nd CP (10 μm) Feb. 10 (1) Avoid stains!

HPR (4 hours) , dry and pack [UPW] Feb. 10-13 (3)

ship to KEK Feb. 14-21 (7)

HPR (8 hours), assemble, baking, T-mapping Feb. 22-28 (7) TTC 2.28 - 3.3

VT, Inspection, back to IHEP Mar. 1-11 (8) Before TTC?

IHEP-02 large grain cavity with HOM

• low loss shape

• end cell w/o HOM optimization

• TESLA HOM coupler

• quasi-TESLA end plate

• tuner and bellow in the middle

• Ti helium vessel

• magnetic shield tubes inside

• magnetic shield end caps outside

• plug-compatibility

• install into IHEP short cryomodule

• distance from input coupler to end cell longer ( > 54 mm)

• total length longer

IHEP-02 End Group

• IHEP-02 will be tested in FNAL or JLAB in 2011 for several times

• try to adopt TELSA flanges and end plate to avoid new tooling, transitions and fixtures, except the input coupler port flange

IHEP-02 Plan

Task Time Notes

Half cells and Dumbbells fabrication Aug – Nov 2010 Zhao’s talk

Dumbbell reshaping and trimming Dec 2010 no iris intensive grind

End Group and Cavity EBW Dec 2010- Mar 2011 visa document

Processing (CBP+CP+HPR) April - May new interfaces in IHEP

Ship to FNAL or JLAB mid June Interfaces preparation

1st VT June

CP or EP and VT (25 MV/m) July - August SRF11: July 24-28

Helium Vessel, bellow, tuner flange Sept CP after jacket welding?

Assemble and install tuner Oct 2011clean room qualityinput coupler cold part

2 K pipe weld, cryomodule install End of 2011

IHEP-02 Interfaces (FNAL)• only 1 of the 6 cavity flanges is different from TESLA

– RF input through input coupler port, fixed coupling (what Qext?)

• order input coupler flange and antenna from Kyocera

• order helicoflex (CS20M45CI15037) from Usui

– make new EP sealing for input coupler port

– bottom flange evacuation (explosive and vacuum valve)

– no electron monitor (top flange blanked)

– HOM coupler pickups blanked

• limited number of thermal sensors– second sound transducers can’t replace T-mapping system

• no CP facility for the 1.3 GHz 9-cell cavity, CBP available

• make same FNAL/ANL jig for EP, HPR, CBP…

• pretuning only vertically (can’t use auto-machine due to shape)– bring manually tuning jig (mid and end) and software

• fixed when Shekhar Mishra visit IHEP (Feb 2011)

IHEP-02 Interfaces (JLAB)

• VT same with FNAL

• EP: cavity length, sealing, slight difference in the beam tube diameter, EP cathode rod available

• CP available

• Kyoto camera and QM1

• limited T-mapping

• horizontal pre-tuning OK

• reduced new interfaces as MHI-08

• sapphire HOM antenna for horizontal test

• order antennas from Kyocera

• Bob Rimmer IHEP visit (Feb 2011)

IHEP-03 fine grain TESLA cavity plan

Task Time Notes

Dies and fixtures Jan - Feb 2011

Half cells and Dumbbells fabrication Mar - June 621 EBW machine?

End Group and Cavity EBW April - July

Processing or not August - September no CBP, no CP

Ship to FNAL or JLAB mid October

Processing and VT (25 MV/m) October - November interfaces no problem

Helium Vessel, bellow, tuner flange? End of 2011

IHEP-03 can be a backup for IHEP-02 module test, except the input coupler port.

Or install to STF phase 2 CM2?

II: BXERL

Beijing Light Source (2016-2025)

Main RingE=5 GeVC=1200m~ 1 nm

BoosterC=300m

250MeVLinac

Return

Gun

5 GeV SRF Linac 1.3 GHz 7-cell Cavities

1100m

650m

I: Low Emittance SR

Beijing Science Park

50 km North of downtown Beijing, include New SRF Lab

ERL test facility cavities

• Similar to KEK cERL

• 35 MeV, 10 mA, 1.3 GHz RF

• Photocathode DC gun and two 2-cell cavities as injector

• Two 7-cell cavities of the main linac

• 2010-2011: design (CDR-0 finished)

• 2012-2013: fabrication and test (6 cavities)

• 2014-2015: dressing, horizontal and beam test

• Input couplers and HOM absorbers are challenging

1515

X区

ERL Test Facility in Hall #1 at IHEP campus

50 m x 12 m = 600 m2

Preliminary cost estimation : ~ 22 M USD

China ADS

IS

SC RFQ

2016CIADS (1.7 B CNY)Reactor ： ~10 MWAccelerator：50 MeV / 10 mA120 MeV ?

2022ADS PrototypeReactor ： ~100 MWAcce ： 600~1000 MeV / 10 mA

2032ADS DemoReactor ： ~1000 MWAccel ： 1.5 GeV/ > 10 mA

Possible site: Ordos, Inner Mongolia

OrdosOrdos

Jin PingJin Ping1800 km1800 km1800 km1800 km

Dayabay I & II CSNS upgrade

BEPCII and BESIII

ADS and China’s Future Neutrino Physics Experiment

ADS

CJPL

2400 m deep2400 m deep

High energy end for the ADS linac

1.3 GHz 9-cell cavity (beta=0.8) SRF accelerator unit (2012-2015)

Linac configuration under discussion

SRF facilities for cavity development

• Vertical test

• Ultrapure water, High pressure rinsing system, clean room

(to be qualified)

• VT Dewar and helium recycling

• New cryogenics system

• T-mapping

• EP for high Q and high gradient

• New SRF lab, EBW machine, press and vertical trimming machine…

Summary

1. IHEP-01 9-cell cavity made the first try on the technique and infrastructures needed for the multi-cell cavity development.

2. IHEP-02 or IHEP-03 will demonstrate the 1.3 GHz SRF integration in IHEP, providing experience for ERL and ADS R&D in China.

3. ILC 1.3 GHz SRF technology will extend to various large scale projects in China - electron or proton, pulsed or CW machines.

4. Infrastructures and industrial partners of certain scale and qualification will soon be the limit for this development.

2006-2010

2011-2015

2020 -2030