1.3 GHz SRF Cavity R&D Plan Jiyuan Zhai ILC Group, IHEP 3 rd IHEP-KEK 1.3 GHz SRF Meeting, 7 Dec 2010, Beijing

Outline 2011 Plan – IHEP-01 (LG LL 9-cell w/o HOM) 2 nd 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), – ADS (beta 0.8, 1.3 GHz 9-cell cavity), CW, High Current

IHEP-01 large grain 9-cell cavity Fabrication: – Processing: st VT: – 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

IHEP-01 defects and reprocessing Quench defects X-ray photo (cell #9 slot) Local grinding (cell #9) CBP Field emitters CP stains – 2 nd 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 / m 1 mm #3, 85° > 21 MV/m equator 1 mm

IHEP-01 2 nd processing and VT schedule Task [preparation]Time (days)Notes Local grind [new inspect tool, X-ray photo]Dec (5)Totally 30 days CBP (100 μm) [jig, stone, maintain]Dec (7)Visa document LPR, ultrasonicDec (2) 1 st 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 (5) Pretuning (vertical), jig modify & fittingJan (5)Holiday 1.29 – nd CP (10 μm)Feb. 10 (1)Avoid stains! HPR (4 hours), dry and pack [UPW]Feb (3) ship to KEKFeb (7) HPR (8 hours), assemble, baking, T-mappingFeb (7)TTC VT, Inspection, back to IHEPMar (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 TaskTimeNotes Half cells and Dumbbells fabricationAug – Nov 2010Zhao’s talk Dumbbell reshaping and trimmingDec 2010no iris intensive grind End Group and Cavity EBWDec Mar 2011visa document Processing (CBP+CP+HPR)April - Maynew interfaces in IHEP Ship to FNAL or JLABmid JuneInterfaces preparation 1 st VTJune CP or EP and VT (25 MV/m)July - AugustSRF11: July Helium Vessel, bellow, tuner flangeSeptCP after jacket welding? Assemble and install tunerOct 2011 clean room quality input coupler cold part 2 K pipe weld, cryomodule installEnd 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 Q ext ?) 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 TaskTimeNotes Dies and fixturesJan - Feb 2011 Half cells and Dumbbells fabricationMar - June621 EBW machine? End Group and Cavity EBWApril - July Processing or notAugust - Septemberno CBP, no CP Ship to FNAL or JLABmid October Processing and VT (25 MV/m)October - Novemberinterfaces 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 ( ) Main Ring E=5 GeV C=1200m  ~ 1 nm Booster C=300m 250MeV Linac 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 : design (CDR-0 finished) : fabrication and test (6 cavities) : dressing, horizontal and beam test Input couplers and HOM absorbers are challenging

15 X区X区 ERL Test Facility in Hall #1 at IHEP campus 50 m x 12 m = 600 m 2 Preliminary cost estimation : ~ 22 M USD

China ADS IS SC RFQ 2016 CIADS ( 1.7 B CNY ) Reactor ： ~10 MW Accelerator ： 50 MeV / 10 mA 120 MeV ? 2022 ADS Prototype Reactor ： ~100 MW Acce ： 600~1000 MeV / 10 mA 2032 ADS Demo Reactor ： ~1000 MW Accel ： 1.5 GeV/ > 10 mA Possible site: Ordos, Inner Mongolia

Ordos Jin Ping 1800 km Dayabay I & II CSNS upgrade BEPCII and BESIII ADS and China’s Future Neutrino Physics Experiment ADS CJPL 2400 m deep

High energy end for the ADS linac 1.3 GHz 9-cell cavity (beta=0.8) SRF accelerator unit ( ) 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