FNALBARC SSR 2 Cryomodule Meeting SSR 2 Team

FNAL/BARC SSR 2 Cryomodule Meeting SSR 2 Team 02/18/2021 A Partnership of: US/DOE India/DAE Italy/INFN UK/UKRI-STFC France/CEA, CNRS/IN 2 P 3 Poland/WUST

Documentation • 3 D models: • SSR 1 Prototype Cryomodule: F 10002433 • SSR 1 Production Cryomodule: F 10142933 • SSR 2 Pre-Production Cryomodule: F 10138829 • SSR 1 Prototype Cryomodule TRS: ED 0009534 • SSR 2 Cryomodule TRS: ED 0009651 • EPDM: • SSR 1 Prototype: ED 0001256 • SSR 1 Production: ED 00011856 • SSR 2 Pre-Production: ED 0001257 2 2/18/2021 M. Parise | FNAL/BARC SSR 2 Cryomodule Meeting

Ongoing design activities • Support post • Strongback • Vacuum Vessel • HTTS • Current leads 3 2/18/2021 M. Parise | FNAL/BARC SSR 2 Cryomodule Meeting

New Support Post Sketch 4 2/18/2021 M. Parise | FNAL/BARC SSR 2 Cryomodule Meeting

Maximum Payload Maximum sustainable payload with proposed geometry: 6500 Kg (14330 lbs) To avoid elastic instability with SF=2 5 2/18/2021 M. Parise | FNAL/BARC SSR 2 Cryomodule Meeting

Strongback on Rails Tolerances suggested by vendor for the bottom support plates (welded to the vacuum vessel): • Flatness within 0. 005’’ (0. 127 mm); • Parallelism between rails within 0. 002’’ (0. 05 mm). 6 2/18/2021 M. Parise | FNAL/BARC SSR 2 Cryomodule Meeting

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PBC LINEAR BEARINGS Pillow Blocks with Roller Bearings Pillow Blocks with Plain Bushing Bearings PROS -Self lubricating -Clean room compatible -130$ each -1. 25’’ shaft CONS -Misalignment may compromise motion 2/18/2021 -0. 125 friction coefficient M. Parise | FNAL/BARC SSR 2 Cryomodule Meeting PROS Adjustable 0. 02 friction coefficient CONS Need grease on shaft Not Clean room compatible 354$ each 1. 5’’ shaft 9

PBC LINEAR BEARINGS Shafting: Breaks option available both with bushing and roller bearings: 20 m long preassembled shaft assembly: -7863$ with roller bearings; -6719$ with bushing bearings; 2/18/2021 M. Parise | FNAL/BARC SSR 2 Cryomodule Meeting 10

Lower HTTS 11 2/18/2021 M. Parise | FNAL/BARC SSR 2 Cryomodule Meeting

Showing Current SSR 2 Layout • Cavity Instrumentation Port on Side Port Side 12 2/18/2021 M. Parise | FNAL/BARC SSR 2 Cryomodule Meeting

Current Connector Layouts • Solenoid Instrumentation Port • • • Solenoid Related Temperature Sensors Coupler e-Probe (2 cavities) Cavity Probe (2 cavities) Voltage Taps BPM 13 2/18/2021 M. Parise | FNAL/BARC SSR 2 Cryomodule Meeting

Current Connector Layouts • Tuner Access Port • • Motor Temperature Stepper Motor Limit Switches Piezos 14 2/18/2021 M. Parise | FNAL/BARC SSR 2 Cryomodule Meeting

Current lead path from magnet to cryostat (1) HTS leads (2) HTS to shield “jump” (3) Feedthrough/thermal intercept (4) Thermal shield (5) Resistive lead (phosphor bronze) (6) Feedthrough flange (cartridge heaters optional) (7) Power cables with plugs (8) Purge box with dry air (one-way open flow) (1) (2) (3) (4) (5) (7) (6) (8) 2/18/2021 M. Parise | FNAL/BARC SSR 2 Cryomodule Meeting 15

Design considerations • Need to bring current from power supply at ~300 K to magnet terminal block at 2 K, with minimal heat load • Conduction-cooled magnet and current leads 300 K • Current leads have 2 parts: • Resistive section made of phosphor bronze bridges 300 K cryostat and thermal shield • HTS leads bridge thermal shield and 2 K magnet • Minimize heat load between thermal shield and 2 K (no Joule heating) but are limited by a warm end maximum operating temperature of 70 K • Heat load at 2 K from all 10 HTS current leads is <0. 35 W compared to ~12. 8 W with previous design • There is no load at 5 K (28. 8 W in previous design) Resistive Shield 50 -60 K HTS • Thermal intercept at shield required • Good thermal contact with shield in order to intercept the dynamic + static 2 K heat load from resistive leads (~22 W for all 10 current leads) • Electrical continuity between resistive and HTS leads • Electrically isolated from thermal shield • HTS temperature highly dependent on shield temperature; largest gradients come from shield (~8 K) 16 2/18/2021 M. Parise | FNAL/BARC SSR 2 Cryomodule Meeting

“Sapphire sandwich” Copper jump Insulating bushing Provides electrical path between feedthrough and HTS lead Electrically insulates hardware from feedthrough Sapphire disc Provides thermal path while maintaining electrical insulation Copper feedthrough Provides electrical path between resistive lead to copper jump G 10 sleeve Electrically insulates feedthrough from shield G 10 retainer plate Holds sapphire in place and electrically insulates feedthrough from shield 2/18/2021 Phosphor bronze resistive leads M. Parise | FNAL/BARC SSR 2 Cryomodule Meeting 17

“Sapphire sandwich”: Assembly steps 2/18/2021 M. Parise | FNAL/BARC SSR 2 Cryomodule Meeting 18

“Sapphire sandwich”: Conclusion • Proposed ”sapphire sandwich” design: • Maintains HTS temperature at or below 70 K limit with a He gas temperature (or shield temperature at He gas line) of up to 60 K • Uses many commercially available components • Custom components are simple to manufacture • Easy to assemble • Inexpensive to produce 19 2/18/2021 M. Parise | FNAL/BARC SSR 2 Cryomodule Meeting

Current lead feedthrough flange • Condensation and icing of the leads on the air side should be prevented • Mitigation possibilities: • Fan to circulate air (interferes with microphonics) • Flowing dry air/inert gas • Heaters on individual leads or flange • Proposed solution: • Purge box with flowing dry air (unsealed, air flow in one direction) with optional cartridge heaters on flange • Purge box should be removable to allow installation of up/downstream components and access to feedthrough plugs • CF seal preferred over o-ring 20 2/18/2021 M. Parise | FNAL/BARC SSR 2 Cryomodule Meeting

Current lead feedthrough flange • Condensation and icing should be avoided • Static/dynamic heat load to 50 K shield are 11 W each for a total powered heat load of 22 W in pre-production SSR 2 • May be reduced to 12 W for production SSR 1/2 • Purge box with dry air at 2 m/s results in flange temperature drop of 15 K • Likely sufficient to prevent icing • Cartridge heaters on flange are optional 21 2/18/2021 M. Parise | FNAL/BARC SSR 2 Cryomodule Meeting