1. Short Pulse X-ray Dampers U1.02.01.03.07 / U1.03.03.07 (U1.02.01.03.05) Geoff Waldschmidt RF Engineer ASD / RF DOE Lehman CD-2 Review of APS-Upgrade 4-6 December 2012

2. Outline  Technical Significance  WBS Scope  Team  Requirements  Design  Interfaces  Value Engineering  Risks  ES&H  Cost  Schedule 2 DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012

3. Technical Significance 3  Dampers (LOM / HOM) –Maintains beam stability –In-vacuum HOM dampers (within cryomodule) –High-power handling: LOM (2kW) / HOM (0.5kW)  Rf Windows (LOM / Input Coupler) –Double windows for redundant vacuum barrier –Wide bandwidth for mode damping –Transmission power handling: LOM (2kW) / input coupler (10kW)  Waveguides (LOM / Input Coupler / HOM) –Required for power coupling and mode damping in the cavity –Designed to meet rf and thermal performance requirements Cavity assembly HOM Damper RF window DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012

4. SPX Dampers and Windows Scope and WBS U1.02.01.03 & U1.03.03 (incl. SPX R&D Cavity/Tuners) 4 LOM window HOM damper Input Coupler window LOM damper DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012

5. The Team 5  APS Personnel –G. Waldschmidt – RF Engineering –B. Brajuskovic – Mechanical Engineering –D. Bromberek – RF testing –J. Fuerst – Mechanical Engineering –J. Liu – Mechanical Engineering –M. Middendorf – Test Stand Manager –G. Wu – Physicist  Cornell performed testing of rf parameters of the SiC material – led by V. Shemelin DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012

6.  Designed for a total beam-induced power of 2.25 kW  PRD outlines longitudinal and transverse damping requirements for beam stability SPX RF Window / Damper Requirements LOM power spectrum 6 FPC: 160 W HOM: 265 W Beam pipe: ~15W LOM: 1.53 kW Beam-induced losses through cavity ports DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012

7. RF Window Designs 7  Windows are procured from CML Engineering –Input coupler windows are “identical” to standard WR284 APS Linac windows –LOM windows are a WR340 version of the input coupler window with optimizations across critical bandwidth  Windows have compact profile for cryomodule envelope  Windows have an average power rating of 15 kW LOM prototype: VSWR (2.2 - 2.4 GHz) LOM prototype: VSWR (2.9 – 3.9 GHz) APS Linac window Pillbox resonance DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012 Critical frequency range: 2.3 GHz and 2.9 – ~4.0 GHz

8.  LOM damper is commercially available 5kW load  HOM damper is designed at ANL (based on PEP-II and KEK designs) and fabricated by industry  HOM dampers consist of a four-wedge design to reduce stresses  Water-cooled  Located inside the cryomodule at 300K Damper Designs 8 LOM damper HOM: RF return loss HOM damper: Four-wedge design HOM: Thermal profile DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012

9. Prototype Dampers 9 RF test port SiC test fixture  Five prototype HOM dampers were successfully fabricated (prior to SPX0 dampers)  Damping material is Hexoloy SA Silicon Carbide (SiC) from St. Gobain - similar material used in ARES cavities at KEK *  Extensive tests were used to pre-qualify material –Particulate and Lifetime –Soldering / Brazing –UHV, ME, and RF properties  Improvements were incorporated into SPX0 design –Expanded eBeam welding and machining –SiC tile soldering –Fixturing enhancements and plasma etching HOM prototype damper High-power test setup DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012 * Operational Experience of HOM Absorbers at KEKB”, International Workshop on Higher-Order-Mode Damping of Superconducting RF Cavities, 2010.

10. SPX0 Damper Production  Identical SiC material was procured for SPX0 dampers –Material failed during cutting (July 2012) –Tomography analysis showed volumetric sub-surface fractures  Recovery plan is being implemented –Multiple SiC materials have been procured –Alternate vendor being developed –Materials are being tested for rf, mechanical, and vacuum properties –Plan was accepted by APS-U (Oct. 2012) –Delivery date has moved from Dec. 2012 to June 2013  Copper damper waveguide bodies and flanges are being fabricated 10 Failed SiC plate SPX0 damper waveguide body DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012

11. Waveguide Requirements (U1.02.01.03.05)  Primary requirement of waveguide is to transmit power to the cavity and dampers  Waveguide geometry must maintain broadband rf performance for HOM / LOM suppression  RF loading of the dampers at 2.815 GHz must be limited  Thermal leak to cooling circuits must be minimized  The waveguide designs achieve these guidelines 11 Cavity with waveguide, helium vessel, and tuner HOM damper HOM waveguide LOM waveguide Input coupler waveguide DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012

12. Dynamic RF Loading 12 Input power vs. Qext for different beam offsets RF simulation geometry Surface loss density Operating point  Dynamic loading of waveguides is due to rf input power and parasitic mode damping  1.86 kW of input power produces 0.5 MV deflecting voltage –Dynamic loss in cavity is 7 W with Q o of 10 9 –Evanescent field decays slowly in end-group waveguides  HOM and LOM waveguides are designed for 300W and 2kW of traveling-wave rf power, respectively Electric field Location of helium vessel DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012

13. Waveguide Heat Load 13 Input Coupler HOM LOM Dynamic loading: (1) 300W @ 3GHz (2) Cavity evanescent field Dynamic loading: 2 kW @ 2.3 GHz Dynamic loading: (1) 1.86 kW @ 2.815 GHz (2) Cavity evanescent field Heat load to 2K due to waveguides: ~7.3W (each cavity) 80K 2K 300K 80K 2K 300K 80K 2K DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012

14. Interfaces  LOM loads and RF windows are supplied by industry  HOM loads will be fabricated by industry with additional support from ANL  RF windows and HOM dampers will be supplied by ANL to JLAB for assembly onto the cavity string  Diagnostics, heating elements for each window / damper, water cooling, and vacuum pumping will be handled by AES group at the APS  Diagnostic signals will be setup by the Controls group in Epics for remote access and data logging 14 DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012

15. Damper / Window Value Engineering  Standard WR284 and WR340 waveguide sizes were used for the HOM / LOM dampers and windows  Modifications of existing designs –Developed WR340 LOM rf window based on the APS Linac WR284 pillbox window –Bellows for both FPC and HOM waveguides were modified from existing WR284 bellows (Darmstadt) 15 DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012

16. Damper / Window Risks and Mitigation  Particulate generation of the HOM dampers – HOM damper design was adapted to reduce particulates – SiC surface is processed to reduce particulate generation – Particulate testing is being performed  Performance and durability of the HOM dampers – SiC material has high thermal conductivity and low permittivity – Manufacturing process is carefully controlled – Soldering of SiC produces consistent and strong bonding  Water freezing in the rf windows / dampers due to 80K thermal intercepts –Water temperature is monitored –Redundant heating elements are located on each component –N 2 gas-purging of water lines is under consideration in case of system power loss  Cavity venting due to RF window vacuum leak –Double window design is used for both the LOMs and input couplers –RF window diagnostics include IR cameras and arc detectors 16 DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012

17. Damper / Window ES&H DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012 17  Integrated Safety Management System (ISMS) –APS-U Project following Argonne’s ISMS program requirements –Argonne Integrated Safety Management System (ISMS) Description recently revised and submitted to DOE ASO Describes framework for integrating ESH requirements with mission objectives References Argonne LMS procedures which implement specific portions of the ISMS  General Safety Requirements –Follow ASD/RF group safety policies –High-power (4 kW) rf testing is performed in 400A at the APS –Personnel and equipment safety interlocks are implemented –Test permits are required to document each experiment and outline the hazards and mitigation steps that are required

18. SPX Dampers and Windows Scope and WBS U1.02.01.03 & U1.03.03 (incl. SPX R&D Cavity/Tuners) 18  Damper (U1.02.01.03.07.01): $657k –HOM detailed design / Fabrication for (2) cavities for SPX0 / SiC / Ebeam welding / Testing –LOM dampers / External waveguide  HOM Dampers (1.03.03.07.01): $543k –HOM damper fabrication for (8) cavities (Design work on dampers is primarily incorporated into WBS U1.02) DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012

19. SPX Dampers and Windows Obligation Profile U1.02.01.03 & U1.03.03 (incl. SPX R&D Cavity/Tuners) 19 DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012

20. SPX R&D and Production Milestones U1.02.01.03 & U1.03.03 20 DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012

21. SPX Dampers and Windows Milestones U1.02.01.03 & U1.03.03 (incl. SPX R&D Cavity/Tuners) 21 DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012

22. SPX Dampers and Windows Summary Schedule U1.02.01.03 & U1.03.03 (incl. R&D Cavity/Tuners) 22 DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012

23. SPX Dampers and Windows BOE Contingency U1.02.01.03 & U1.03.03 (incl. SPX R&D Cavity/Tuners) 23 DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012

24. Work after CD-2  Complete HOM damper fabrication for SPX0  Procure LOM dampers, LOM windows and input coupler windows  Perform low-power and high-power testing / conditioning of dampers and windows  Perform tests on copper prototype cavity to characterize damping  Create design of external waveguide transmission lines for LOM damper and input coupler 24 DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012

25. Summary 25  The scope and cost of the dampers and windows are understood.  The damper and window system is based on requirements defined in the PRD for beam stability and the ESD for power handling.  The preliminary design is complete and the dampers and windows are in the process of procurement.  Resolution of issues with Hexoloy SA damping material for the SPX0 dampers is progressing.  Extensive testing of the dampers and windows will be performed.  Delivery to JLAB for SPX0 is 6/2013 and for SPX is 5/2017  The cost is $4,085k  We are ready for CD-2 DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012