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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 Decem ber 2012. Outline. Technical Significance WBS Scope Team Requirements
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Short Pulse X-ray DampersU1.02.01.03.07 / U1.03.03.07 (U1.02.01.03.05) Geoff Waldschmidt RF Engineer ASD / RF DOE Lehman CD-2 Review of APS-Upgrade4-6 December 2012
Outline • Technical Significance • WBS Scope • Team • Requirements • Design • Interfaces • Value Engineering • Risks • ES&H • Cost • Schedule DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012
Technical Significance • 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 HOM Damper RF window Cavity assembly DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012
SPX Dampers and Windows Scope and WBSU1.02.01.03 & U1.03.03 (incl. SPX R&D Cavity/Tuners) HOM damper LOM damper LOM window Input Coupler window DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012
The Team • 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
SPX RF Window / Damper Requirements Beam-induced losses through cavity ports LOM: 1.53 kW • Designed for a total beam-induced power of 2.25 kW • PRD outlines longitudinal and transverse damping requirements for beam stability HOM: 265 W Beam pipe: ~15W FPC: 160 W LOM power spectrum DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012
RF Window Designs APS Linac window • 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) Pillbox resonance Critical frequency range: 2.3 GHz and 2.9 – ~4.0 GHz DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012
Damper Designs HOM damper: Four-wedge design • 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 LOM damper HOM: RF return loss HOM: Thermal profile DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012
Prototype Dampers HOM prototype damper • 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 eBeamwelding and machining • SiC tile soldering • Fixturingenhancements and plasma etching High-power test setup SiC test fixture RF test port *Operational Experience of HOM Absorbers at KEKB”, International Workshop on Higher-Order-Mode Damping of Superconducting RF Cavities, 2010. DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012
SPX0 Damper Production Failed SiC plate • 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 SiCmaterials 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 SPX0 damper waveguide body DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012
Waveguide Requirements (U1.02.01.03.05) Cavity with waveguide, helium vessel, and tuner HOM damper • 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 HOM waveguide LOM waveguide Input coupler waveguide DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012
Dynamic RF Loading RF simulation geometry • 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 Qo of 109 • Evanescent field decays slowly in end-group waveguides • HOM and LOM waveguides are designed for 300W and 2kW of traveling-wave rf power, respectively Surface loss density Input power vs. Qextfor different beam offsets Location of helium vessel Electric field Operating point DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012
Waveguide Heat Load HOM Input Coupler 300K 300K 80K Dynamic loading: (1) 1.86 kW @ 2.815 GHz (2) Cavity evanescent field 80K 2K 2K Dynamic loading: (1) 300W @ 3GHz (2) Cavity evanescent field LOM 300K Dynamic loading: 2 kW @ 2.3 GHz 80K 2K Heat load to 2K due to waveguides: ~7.3W (each cavity) DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012
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 DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012
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) DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012
Damper / Window Risks and Mitigation • Particulate generation of the HOM dampers • HOM damper design was adapted to reduce particulates • SiCsurface is processed to reduce particulate generation • Particulate testing is being performed • Performance and durability of the HOM dampers • SiCmaterial 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 • N2 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 DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012
Damper / Window ES&H • 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 DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012
SPX Dampers and Windows Scope and WBSU1.02.01.03 & U1.03.03 (incl. SPX R&D Cavity/Tuners) • 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
SPX Dampers and Windows Obligation ProfileU1.02.01.03 & U1.03.03 (incl. SPX R&D Cavity/Tuners) DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012
SPX R&D and Production Milestones U1.02.01.03 & U1.03.03 DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012
SPX Dampers and Windows Milestones U1.02.01.03 & U1.03.03 (incl. SPX R&D Cavity/Tuners) DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012
SPX Dampers and Windows Summary Schedule U1.02.01.03 & U1.03.03 (incl. R&D Cavity/Tuners) DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012
SPX Dampers and Windows BOE Contingency U1.02.01.03 & U1.03.03 (incl. SPX R&D Cavity/Tuners) DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012
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 DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012
Summary • 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