FNAL Superconducting RF Program Fermilab Annual Science and Technology Review September 5-7, 2012 Bob Kephart

Outline Goals, Approach, and Context of FNAL SRF Program Accomplishments & Status  Effectiveness and impact of the SRF Program  Leadership and creativity of the FNAL SRF staff  Productivity of SRF facilities at FNAL Changes FY12  FY13 Plans for FY13 and beyond ES&H & QC Summary Bob Kephart, Sept 2012 Fermilab S&T Review2

Goals of the Fermilab SRF Program Support the strategic goals of the U.S. HEP program  Intensity frontier: Project X  Energy frontier: International Linear Collider (& Muon Collider) Develop low-beta SRF cavities and cryomodules for the acceleration of high intensity Proton beams Develop  =1 SRF cavities and cryomodules for ILC and/or the Project X pulsed linac (3-8 GeV) Develop related SRF infrastructure and technology that can be applied to future Office of Science projects U.S. SRF Industrialization to permit fabrication of future projects Bob Kephart, Sept 2012 Fermilab S&T Review3

General Approach of the R&D Effort Build on experience  Take full advantage of existing U.S. SRF capabilities and infrastructure (close collaboration with ANL, JLAB, and Cornell)  International Collaborations (DESY, KEK, INFN, etc)  Extensive network of collaborators ( 23 agreements in place) Contribute to existing programs Participation in global ILC R&D program Enable new programs  Project X at Fermilab Establish new collaborations  Collaboration on NGLS, APS-U  Collaboration with India, ESS, Korea (RISP)  Crab cavities for LHC CERN ? Bob Kephart, Sept 2012 Fermilab S&T Review4

Context of SRF Activity at Fermilab SRF activities are supported by four B&R’s:  General Accelerator Development  SRF Infrastructure  ILC R&D Program  Accelerator Operations Test stand and cryo operations, etc. Plus one-time ARRA SRF funds of ~$53 M in FY09 Fermilab SRF activities are managed as an integrated program to avoid duplications and promote efficiency Because of past emphasis on ILC R&D  There is substantial ongoing activity on 1.3 GHz technology  R&D on gradient, quality factor, and manufacturing yield  Development of US cavity vendors (ARRA procurements)  Cavity process/test and construction of 1.3 GHz cryomodules Bob Kephart, Sept 2012 Fermilab S&T Review5 Primarily 1.3 GHz beta = 1 Low beta cavities for PX

Context of SRF Activity at Fermilab Adoption of a 3 GeV CW linac followed by a 3-8 GeV pulsed linac for Project X in 2010 results in a powerful new intensity frontier machine, but presents new challenges  Need six different cavities optimized for changing velocity (  ) of Protons  Four different frequencies (162.5, 325, 650, 1300 MHz)  Five of these cavities are completely new for Project X (vs. 2 for SNS)  CW cavities  large heat loads, 2 K operation  changes to CM designs  Operation at significantly higher gradients than SNS to reduce costs The development of these cavities & CM is a major new effort  A strong R&D program is needed to reduce risks and costs  Need to design, order, process new cavity types and cryomodules  Benefits enormously from the SRF infrastructure and the experience gained with 1300 MHz cavities and CM…  Actively modifying our SRF infrastructure to address the new challenges associated with PX cavities and CM (Modest changes since much was generic) Bob Kephart, Sept 2012 Fermilab S&T Review6

PX SRF Linac Technology Map Bob Kephart, Sept 2012 Fermilab S&T Review  =0.11  =0.22  =0.4  =0.61  = MHz MeV  = GHz 3-8 GeV ILC MHz MeV 650 MHz GeV SectionFreqEnergy (MeV)Cav/mag/CMType HWR (  G =0.11) /6/1Half Wave, solenoid SSR1 (  G =0.22) /8/ 2Single Spoke, solenoid SSR2 (  G =0.47) /20/4Single Spoke, solenoid LB 650 (  G =0.61) /14/75-cell elliptical, doublet HB 650 (  G =0.9) /19/195-cell elliptical, doublet ILC 1.3 (  G =1.0) /28 /289-cell elliptical, quad CW Pulsed 7 SRF part of PXIE Project Cost Risk

HWR (  = 0.11 ) Half Wave Resonator (collab ANL)  Cavity design complete, ordering parts, CM design in progress  Very similar to cavities & CM already manufactured by ANL  Optimize to achieve tight packing in PX front end SSR1 (  = 0.22 ) Single Spoke Resonator  Started under HINS program and is therefore more advanced  Two prototypes fabricated by industry, processed in collaboration with ANL, and tested at Fermilab as part of HINS  One cavity dressed with He vessel, coupler tuner  Two cavities in fabrication at IUAC-Delhi ( Q3 FY13 )  Ten cavities fabricated by US industry (6 have arrived, 2 tested)  Tests in progress (next slides) SSR2 (  = 0.47 )  EM design complete  Mechanical design is advanced  Prototype in FY13-14 Accomplishments and 325 MHz Cavities Bob Kephart, Sept 2012 Fermilab S&T Review8

325 MHz Test Capabilities Developed Bob Kephart, Sept 2012 Fermilab S&T Review SSR-1 prototypes are tested in the VTS-1 vertical dewar (normally used for 1.3 GHz cavity testing ) with the addition of new electronics and tooling. Spoke Test Facility enables testing of “dressed” 325 MHz single-spoke resonators. Operated previously at 4.8 K (pulsed RF) Upgrades for 2 K CW operation in process Dressed SSR-1 Includes RF couplers, tuners, and magnetic shielding Prototype tested in STF, excellent results at 4.8K Bare Dressed 9 STF

SSR1 Fabrication at Roark

Status of New 325 MHz SSR1 Cavities Received 6 cavities of 10: Performed incoming inspections (Visual, CMM, leak check, RF) Two cavities (S105, S107) processed and cold tested, Excellent results Ordering parts to dress cavities Cavity (S106) has a leak and is being repaired, S111 requires EBW repair of hole Bob Kephart, Sept 2012 Fermilab S&T Review11

New SSR1 Prototypes Exceed PX Performance Specs. Bob Kephart, Sept 2012 Fermilab S&T Review12 Two previous SSR1 spoke resonators performed very well in bare cavity tests This is first test of 2 cavities from U.S. Vendor (Roark) production of 10 cavities Performance at 2 K is above requirements for Project X in both Q 0 and gradient Revised design of helium vessel and tuner are nearly complete Ordering parts Expect to dress cavities in FY13 for first SSR cryomodule Bare cavity at 2 K micron BCP and HPR at ANL/FNAL processing facility then 120 C bake Low FE depends on optimized nozzle design for effective HPR of surface

650 MHz Cavity Development & Prototypes 650 MHz cavities/cryomodules are cost drivers for Project X  Studying cost reduction methods & Q 0 improvement Status & Prototypes:  Two single-cell  = 0.6 cavities prototyped at JLab  Six single-cell  = 0.9 cavities prototyped recently received from U.S. industry, Four five-cell  = 0.9 cavities ordered (AES)  5 additional single cell and 5 five-cells  = 0.9 cavities ordered from industry (PAVAC) on ARRA funds  Prototypes at both  are also being fabricated in India Bob Kephart, Sept 2012 Fermilab S&T Review13 5-cell EM and mechanical design complete CAD Rendering!

650 MHz Cavity Processing & Testing Infrastructure modifications: for 650 MHz complete FNAL: Vertical Test Stand: Electronics, top plate FNAL: Cavity handling & HPR tooling, etc. FNAL: Optical inspection system modifications ANL: New electro-polishing tool operational for QWR/HWR and ~ for 650 MHz cavities Prototype tests: Single cells processed at JLab. VTS tests at both JLAB and ANL/FNAL Both single-cell  = 0.6 cavities show excellent Q 0 at low field dropping at Project X gradients Single cell  = 0.9 cavities will be processed and tested at ANL/FNAL in the Fall Expect 1 st five cell cavities from AES in Q1 FY13 Bob Kephart, Sept 2012 Fermilab S&T Review MHz 1-cell  = 0.6 test at JLAB

Bob Kephart, Sept 2012 Fermilab S&T Review 15 Helium Vessel and Tuner Design Developing 650 MHz helium vessel  Large heavy assembly vs MHz, challenges for handling and test 650 MHz tuner design  Tuner shown is scaled-up blade tuner  Larger thicker walled cavity result in large forces (motor power and lifetime)  Also examining end lever and wedge (India) tuner designs

650 MHz CM Design Status Bob Kephart, Sept 2012 Fermilab S&T Review16 Cryomodule conceptual design advanced Very high heat flux (over 200 W per CM) Stand-alone 8-cavity cryomodule Variant of ILC cryomodule 3-D CAD models, collaboration with India

1300 MHz Development for ILC and PX Goals: ILC SRF goals  S0 >35 MV/m bare cavities  S MV/m dressed cavities in a ILC Cryomodule  S2 Beam test of full ILC RF unit (CM, klystron, modulator)  Build and test ~ 1 CM/yr  All of this will benefit the 3-8 GeV pulsed linac for Project X Accomplishments:  Excellent progress on gradient improvement  ANL/FNAL EP facility: world class throughput & yield  18 Dressed cavities, CM2 populated with 35 MV/m cavities, have >8 good cavities tested in VTS for CM3  Parts for 4 more 1.3 GHz cryomodules ( ARRA funds)  Cost reduction (e.g. tumbling vs. EP, & cavity repair) Excellent progress on all of these CM1 tests complete, CM2 installation in progress Bob Kephart, Sept 2012 Fermilab S&T Review17

Facility Throughput Bob Kephart, Sept 2012 Fermilab S&T Review 18 Steady throughput from ANL/FNAL processing, VTS, and HTS VTS HTS ANL/FNAL EP Processing Status Sep.30, 2011 Status June 30, 2012 Status June 30, 2012

ILC PX ANL/FNAL facility contributing Heavily to ILC gradient program New vendor Pits in EB weld HAZ

Project X Cavity and CM development Project X is powerful, but ambitious (high power, CW, advanced chopper, etc.) Lots of cavity and cryomodule development remains to lower Project risk Bob Kephart, Sept 2012 Fermilab S&T Review20

SRF Materials Research SRF Materials R&D program focuses on  Scientific understanding of SRF surfaces leading to:  High gradients, Improved Q 0, and manufacturing yield  Nano-scale understanding of performance limitations  Targeted cavity process improvements  Material Quality Control (Nb spec., eddy current scan, optical inspection)  EP Science and ICPA  Study H uptake and hydride precipitates leading to Q slope  Leverages collaborations with Universities and other institutions  Multiple ongoing university research initiatives ~10 students/post docs  Game-changing improvements (Nb film deposition, NbN coatings, plasma clean)  Have attracted excellent young research team, doing great work! SRF Materials R&D level of effort:  ~7 FTE staff, ~$600K M&S, including operations of ICPA Bob Kephart, Sept 2012 Fermilab S&T Review 21

Improving the Niobium Supply Recent batch: High tensile strength Too many dislocations Pitted cavities Batch delivered in 2009 Low tensile strength Few dislocations No pitting after EP Niobium vendor found a new process that is less variable and exceeds our spec. Unfortunately, the new sheets were not compatible with later processing. Our SEM upgrade showed why, and led to a tighter specification. Reference: Alex. Romanenko results Bob Kephart, Sept 2012 Fermilab S&T Review 22

Centrifugal Barrel Polish Breakthrough in the FNAL Drastic reductions in acid use. Mirror-like inner surface Demonstrated cavity gradients > 35 MV/M FNAL CBP design has been adopted by several other SRF institutions C. Cooper Recipe Media Bob Kephart, Sept 2012 Fermilab S&T Review23

Cavity Results – CBP Repairs Demonstrated as a cavity repair method. Likely we can ultimately do NO chemistry! Exactly the process you want if want to apply coatings to cavities (e.g. NbN or Nb-Cu) Previously limited here ACC015 Before CBP After CBP and 40 microns EP – Pit completely removed Bob Kephart, Sept 2012 Fermilab S&T Review 24 EP, 2 K CBP, 2 K CBP, 1.8 K EACC vs. Q 0 TE1CAT003 CAT003 After EP CAT003 After CBP

SRF World record cavity Q0’s with NbN Early result, but a potential game changer for SRF CW applications! (LG cavity; quench limited by defect) Bob Kephart, Sept 2012 Fermilab S&T Review25 Reference: Anna Grasselino results

FNAL SRF Infrastructure Goals : Build SRF infrastructure at FNAL including large cryogenic & RF systems and test facilities that are hard for industry to provide Planned infrastructure either complete & operational or well into construction Bob Kephart, Sept 2012 Fermilab S&T Review26

Final Assembly HTS VTS String Assembly MP9 Clean Room VTS New Vacuum Oven Cavity tuning machine New FNAL SRF infrastructure VTS2 Dewar

New NML Buildings Complete (ARRA funded ) Bob Kephart, Sept 2012 Fermilab S&T Review New Cryomodule Test Facility New K refrigerator (under fabrication in industry) will be located in CMTF bldg New Electronics building above tunnel extension Compressor building 28 PXIE

NML: RF Unit Test Facility 29 Bob Kephart, Sept 2012 Fermilab S&T Review29 1st Cryomodule tests complete

NML Status and Plans Bob Kephart, Sept 2012 Fermilab S&T Review CM2 installation CM1 tests complete, swapping for CM2, high gradient CM, All U.S. Processed Cavities 30 Learning a lot! (CM assembly, tuners, LLRF, finding leaks in CM, etc.) Installing 40 MeV photo-Injector (end of FY13)…. However…. OHEP instructions to stop NML build out to full ILC RF unit is a major change (Details on Next slide) CM1 ave gradient = 23.7 MV/M CM2 ave gradient = ~35 MV/M

Changes FY12  FY13 July 2012 OHEP briefing on SRF OHEP reaffirmed importance of SRF but FY13 budgets very constrained ILC R&D funding ends in FY12  National ILC R&D program terminated with the completion of the TDR and end of the GDE mission in June 2013  FNAL ILC B&R funding FY12 = $ 8.8 M  $ 0 in FY13 No ramp up of Project X cavity development Project X construction start now envisioned late in this decade SRF infrastructure B&R reduced ($ 12.5  $ 9.5 M) Instructions from OHEP to terminate completion of NML beam test facility (operate injector & 1 CM, but not full RF unit & beam) Rationale: Primary justification was as the RF unit test facility for ILC Completion requires formal proposal for ASTA as AARD facility Overall SRF program in FY13 shrinks ($ 38.7M to $ 29.3 M)  29 % reduction in SRF workforce vs. FY11 ( 37 FTE reduction) Very painful since we have worked hard to build this workforce Bob Kephart, Sept 2012 Fermilab S&T Review31

Plans: FY13 and beyond Cavity development for Project X (slower than expected pace)  Process and test SSR1 and 650 MHz cavities from industry and India  Complete design and dress both SSR1 & 650 MHz cavities  Collaborate with ANL on HWR work  SRF materials R&D aimed at improved Q0 and cost reduction 1300 MHz development  Process and test 1300 MHz cavities to gain experience and provide feedback to U.S. industry; serial assembly of CM3, … (lower priority than low beta work)  Test CM2 at NML (1 st high gradient CM)  Test long-pulse operation at NML for Project X pulsed linac Infrastructure  Complete ARRA tasks: VTS 2/3, CMTF, etc  Install super-fluid refrigerator at CMTF  Complete injector at NML by end of FY13  Submit AARD proposal for ASTA Management: Manage all this as an integrated whole Bob Kephart, Sept 2012 Fermilab S&T Review32

ES&H and Quality There are many potential hazards associated with SRF  Cryogenics, high pressures, RF, strong acids, etc  Must assure safe operation of equipment/facilities Functional Requirements Specifications  Insure all intended functionality is clear to design team  In use for PX components and SRF infrastructure Many Technical Reviews (examples)  VTS 2/3 cryostat, HWR cavity design, SSR1 cavity and CM, 650 MHz cavity design, New superfluid cryoplant, CM2, etc Many Safety Reviews  Operational Readiness Reviews for facilities: VTS, HTS, CAF, NML,CM1&2, vacuum ovens, ICPA, ANL EP facility, etc  Reviews of components: Dressed cavity, CM2 safety review, No injuries in FY12. Doing a lot… but doing it safely Extensive cavity and cryomodule QC effort! Bob Kephart, Sept 2012 Fermilab S&T Review33

Summary SRF is a powerful enabling technology envisioned for essentially all new accelerators in support of OHEP and SC projects.  Key element in any OHEP plan for Accelerator stewardship SRF R&D program at FNAL is productive & successful  Supports both Project X, ILC, and other Office of Science strategic goals  Leverages existing FNAL infrastructure (bldgs., cryo, etc)  Lots of infrastructure is now in operation and is being used effectively  Leveraging existing SRF collaborations and building new ones  Focused effort to transfer SRF technology to U.S. Industry Adjusting to significant changes in program emphasis (ILC  PX) Have an excellent team in place with growing SRF expertise and an already impressive list of achievements Bob Kephart, Sept 2012 Fermilab S&T Review34

Recommendations from FY11 S&T Review FINDINGS The goal of the Fermilab SRF program is to support the strategic goals of the U.S. HEP program at the intensity frontier (Project X) and at the energy frontier (International Linear Collider and Muon Collider) Project X cavity R&D is being done in this program A key activity in this area is the development of cryomodule engineering and testing The low initial energy of the first SRF stage (perhaps as low as 2.1 MeV) is unique COMMENTS Fermilab is building expertise in cryomodule capabilities, including the Cryomodule Test Facility Fermilab’s focus on transferring capabilities to industry is key to keeping US industry involved and is to be encouraged RECOMMENDATIONS None Bob Kephart, Sept 2012 Fermilab S&T Review36 We agree!