SRF Infrastructure Changes Required for a CW linac Robert Kephart FNAL AAC Meeting November 16, 2009

f R Kephart AAC meeting Nov 16, Aligned SRF efforts ILC SRF R&D SRF infrastructure Project X SRF linac R&D HINS SRF R&D ILC/SRF R&D focus: R&D on a pulsed 1.3 GHz,  =1 for ILC or (Project X; ICD-1, namely a pulsed 8 GeV linac) –SRF program funds infrastructure related to this activity HINS focus: R&D to develop the front end of a 25 ma pulsed linac for Project X; ICD-1 (started during Proton Driver era) –Funds some infrastructure (e.g. 325 MHz HTS cryostat) but not all that would be required for Project X front-end construction This talk: –Review the infrastructure we currently have or are building –Discuss changes required if Project X becomes a 2.x GeV CW linac 2 Working to pursue these in a coordinated way

f R Kephart AAC meeting Nov 16, 2009 ILC/SRF & Project X Integrated Plan At the April 09 ILC DOE review, and again at the May 09 DOE SRF review, showed an integrated ILC/SRF/Px plan for  =1 cavities and cryomodules Goal of this integrated plan was to achieve by FY15: –Capability to build 1 CM/month –Tested RF units (with beam) for ILC or Px (ICD-1) –U.S. Industrial base capable of fabricating 1.3 Ghz Cavities & Cryomodule parts 1.3 GHz RF power components Assumed: $ 36 M/yr for ILC + SRF + $ 52.7 M of ARRA funds Assumed HINS & Project X fund beta < 1 work Plan did not include infrastructure for: –Spoke resonator processing, 325 MHz CM assembly, or test –Any CW testing or operations 3

f R Kephart AAC meeting Nov 16, 2009 ARRA SRF Funds ($ 52.7 M) ARRA SRF: One time infusion of funding –Restores scope removed as result of the FY08 Omnibus Bill –Funds big ticket Infrastructure not previously funded: e.g. New NML buildings and large 1.8 K NML refrigerator –Fund new scope Cavity & EP industrialization, Industrial cryomodule parts, develop HF free process –Advance other planned SRF infrastructure needed to be ready for Project X by 2015 or ILC participation ~2018 All M&S (80% goes to SRF industry) Vacuum oven, 10 MW 1.3 GHz Klystron, VTS 2, HTS-2 RF 40 Cavities, 30 RF Couplers, parts for 2 cryomodules Industrial EP, Eco-friendly cavity processing R&D NML: beamline components, large cryoplant, buildings 10% goes to collaborators (ANL,SLAC, TJNAF) Stimulus funding is focused on infrastructure for pulsed linac –Tight DOE milestones unclear what flexibility, if any, we have for changes 4

f R Kephart AAC meeting Nov 16, 2009 Integrated ILC-PX SRF Plan (May 09)

f R Kephart AAC meeting Nov 16, Cavity/CM process and Testing Plan… Develop in labs then transfer technology to industry Pass! Surface Processing Cavity Fabrication Vertical Testing He Vessel, couplers, tuner HPR or reprocess Horizontal Testing Cold String Assembly Pass! Fail!

f R Kephart AAC meeting Nov 16, SRF Infrastructure High gradient cavities require extensive infrastructure Bare cavities –Fabrication facilities ( e.g. Electron beam welders) –Buffered Chemical Polish facilities ( BCP ) –Electro-polish facilities ( EP ), Large Vacuum Ovens –Ultra clean H 2 0 & High Pressure Rinse systems –Vertical Test System ( Cryogenics + low power RF ) Cavity Dressing Facilities (cryostat, tuner, coupler) –Automatic welders, Class 10 clean room –Horizontal Test System ( cryo and high power pulsed RF ) String Assembly Facilities –Large class 10/100 clean rooms, Large fixtures –Class 10 enclosures for cryomodule inner connects Cryomodule test facilities –Cryogenics, pulsed RF power, LLRF, controls, shielding, etc. –Beam tests  electron source (e.g. FNPL Photo-injector) Expensive, long lead times, Needed for ILC or Project X start

f R Kephart AAC meeting Nov 16, Accomplishments Steady progress on SRF technology at FNAL Several new SRF facilities now in full operation –Vertical Test Stand; tests bare cavities 35 tests so far Civil construction just completed for 2 more VTS systems –Cryomodule Assembly Facility 2 CM assembled in MP9 & ICB Infrastructure to dress cavities (He vessels, tuners, couplers) –Horizontal Test Stand; tests dressed cavities (unique in U.S.) 6 tests so far (5 for 3.9 GHz CM) Production testing of 1.3 GHz cavities is starting –ANL/FNAL Joint EP Processing; commissioning Excellent results with single cells and HPR of 9 cell cavity. Three nine cells EP processed with full facility Mixed results, one ~32 MV/M, one 30  26 MV/M with FE, one ~12 MV/M –RF unit test facility at New Muon Lab; under construction FY09 Accomplishments

f R Kephart AAC meeting Nov 16, Cavities: 48 ordered, 22 from U.S. industry –ARRA funds  another 40 from U.S. industry Cryomodules: Assembled 2 CM with CAF –CM1 = Type III + assembled from DESY kit of parts –Designed/assembled a 3.9 GHz CM for DESY –Parts in hand for cold mass of a 2 nd type III + CM –Began dressing cavities this summer 4 nine cell cavities have He tanks welded for dressing Need 8 for CM2 and 2 for S1 Global CM at KEK –ILC Type IV/Px CM design is complete and ordering parts SRF Materials: Program established (DOE praise + $ 500K) –Single-cell program for U.S. cavity vendor development –EP process development for ANL/FNAL joint system –Improved diagnostics (thermometry, optical inspection) –Understanding reasons for poor performers (weld pits) FY09 Accomplishments

f R Kephart AAC meeting Nov 16, recent U.S. 9-cell cavities (AES) 3 VTS tested >35 MV/M Plot from R Geng, Jlab FY09 Accomplishments Industrialization –ILC cavities built by U.S. vendors (AES, Roark/Niowave) –Three AES cavities have made ILC gradient! –Engaging U.S. industrial vendors in surface processing –Several vendors producing cm parts –ARRA funds are a huge boost Extensive network of SRF collaborations –MOU’s with 18 institutions –Benefitting enormously from collaborations with DESY, JLAB, KEK, Cornell, etc DOE reviews –FNAL role in ILC ART (April 2009) –SRF program (May 2009) –Comments at both uniformly positive

f R Kephart AAC meeting Nov 16, Progress: Cavity Gradient and Yields ILC Px Yield is an Issue  for both ILC and Project X Still need R&D to improve this ICD-1 ICD-2 ILC DESY + JLAB Data from “XFEL qualified vendors”

f R Kephart AAC meeting Nov 16, 2009 Final Assembly HTS VTS String Assembly MP9 Clean Room VTS 1 st U.S. built ILC/PX Cryomodule 1 st Dressed Cavity Cavity tuning machine New FNAL SRF infrastructure

f R Kephart AAC meeting Nov 16, 2009 Bunch Compressor ILC RF unit Diagnostics Gun CC I,II Laser 3 rd har Test Area ~ 22 M 72 M Existing Building New Enclosure New ILC like tunnel 2 nd ILC RF unit Test Areas RF Equipment RF Unit Test Facility at NML Overall Plan: Test RF units: Px, ILC S1 & S2 goals ILC: 3 CM, Klystron, Modulator, LLRF Move A0 Injector to provide ILC like beam New Tunnel Extension: design to allow 2nd RF unit, diagnostic beam lines, AARD facility New Building: Cryoplant, Cryomodule Test Stands 13

f R Kephart AAC meeting Nov 16, 2009 RF Unit Test Facility at NML 14

f R Kephart AAC meeting Nov 16, st Cryomodule installed Large Vacuum Pump Control Room He Refrigerator Progress at NML CM Feed Can Capture Cavity NML Operated at 2K 15

f R Kephart AAC meeting Nov 16, 2009 New buildings and Refrigerator (ARRA) 16

f R Kephart AAC meeting Nov 16, 2009 Implications of CW Linac Project X physics studies of a rare decay program motivate investigation of a 2 MW CW linac in the energy range GeV –Might be married either to a Rapid Cycling Synchrotron or a pulsed linac to meet the LBNE requirement (ICD-2) –Various staging options are under consideration. –Might build this first! (Recent Kovar Px briefing) If ICD-2 is adopted for Project X then additional SRF infrastructure is required for R&D and construction –Some because we had not included it in the past, some because it is a new requirement for a CW linac –Available funding and staff may force some hard choices Redirect the pulsed HINS R&D effort to CW? Reduced R&D effort on a beta=1 pulsed linac for ILC? 17

f R Kephart AAC meeting Nov 16, 2009 Project X: CW infrastructure Need CW capable HTS for 1.3 GHz nine cells –ICD-2 plan is to operate ILC cavities CW at ~ 18 MV/M –HTS is an ideal test platform Important to understand CW HOM heating by fundamental Important to demonstrate CW capable main RF couplers He supply pipe on cavities made to date is probably too small –Estimated ICD-2 heat load/cavity ~ 30 W at 1.8 K  MDB refrigerator total capacity (60 W) is probably adequate but perhaps not with HINS loads operating at the same time Need to understand max heat load supportable by HTS plumbing in 1.8 K CW operation (may need modifications) –Need a new CW RF power source for existing HTS in MDB 18

f R Kephart AAC meeting Nov 16, 2009 Project X: CW infrastructure Need CW capable test dewar for 325 MHz dressed spoke resonators –SSR1, SSR2, TSR –Current HINS test cryostat is designed for 4 K operation vs plan to operate spokes at 1.8 K in Project X, ICD-2 –Estimated cost to modify cryostat for 1.8 K is about $ 40 K +.5 FTE-year –Must also modify feed boxes, etc. (probably > $ 40 K, see Webber talk) –Same question on MDB refrigeration capacity. CW RF power: –Need Project X-like CW RF power sources at 325 MHz, and 1.3 GHz for test stands –Will be needed for component development, LLRF testing, etc CW couplers: –Need CW coupler test facility for both 1.3 and 325 MHz –Current coupler test facility for 1.3 GHz XFEL couplers is at SLAC and is supported by ILC (Need additional CW RF sources) 19

f R Kephart AAC meeting Nov 16, 2009 Project X: CW infrastructure Need infrastructure for assembly of spoke cryomodules. –Likely to be quite different from ILC/XFEL cryomodules –Magnetic focusing and spoke cavities shapes very different –If we adopt the ATLAS "hung from top plate" design assembly fixtures and techniques would be quite different from ILC (CAF) Do we need to be able to test completed cryomodules before installation in the machine? If yes, then need CW capable 1.3 GHz CM test stand at NML –Plan is that Indian engineers will help FNAL engineers to modify the current XFEL cryomodule design before we fabricate it. –ARRA supplied NML refrigerator will have capacity to test one full 1.3 GHz cryomodule on a test stand but ~nothing else can operate at NML at the same time (may be partial work-around’s to this) If yes, then need CW capable 325 MHz CM test stand at NML –No Cryomodule design  no design or plan for test stand Alternative= no tests of CM except in Px linac… implications ? 20

f R Kephart AAC meeting Nov 16, 2009 Project X: CW Questions Personnel: –Laboratory staff is already stretched thin –Difficult to find enough people for pulsed linac work –CW will add additional tasks, so would RCS development –Not clear how we as a laboratory manage to do all this Future of HINS? –Difficult to support CW spoke and front end development while completing current pulsed HINS front end program If we choose RCS for 2.x  8 GeV –ICD-2 would allow U.S. to build ILC-like cavities and CM and aid ILC industrialization –But.. what is the future of the pulsed 1.3 GHz effort at FNAL? ILC funding alone cannot sustain pulsed linac effort If significant SRF funds are diverted to CW infrastructure, then need more funding or we have to drop something (e.g. Do we finish NML as a pulsed facility ?) –How all this ultimately effects the U.S. ILC effort is unclear 21

f R Kephart AAC meeting Nov 16, Conclusions There is lots of technical progress –3.9 GHz CM has been delivered and is a success –Lots of SRF infrastructure for now in operation –Lots more under construction –SRF components in production (cavities, cryomodules, RF power) ILC R&D –Priority reaffirmed by HEPAP/P5 –..but ILC questioned because of large cost –FNAL ILC focus is on SRF But also a key player in the global effort (CFS, GDE office, etc) –Project X dependent on continued funding of ILC SRF activities

f R Kephart AAC meeting Nov 16, Conclusions (2) Integrated 5 yr plan for ILC/SRF/Px R&D & infra exists –Reviewed by DOE in May 09 –Infrastructure & development of  =1 cavities and CM for ILC and Px –Assumed Px (ICD-1) was a pulsed linac –Goal of the plan was to prepare FNAL for building one  =1 ILC-like CM/ month for Project X by FY15 or ILC participation in 2018 Significant changes needed if we are to support CW linac R&D Working on a complete plan for  < 1 infrastructure for Px and … A new plan for CW infrastructure needed if we adopt a CW linac Lots of questions, working on answers, your advice is most welcome