July LEReC Review July 2014 Low Energy RHIC electron Cooling Roberto Than CRYOGENICS SYSTEM

July Outline Cryogenic System Scope and Interface System Description Cryogenic loads and system requirements Procurements Relocated equipment –used/shared/repurposed –Moved to make space Equipment installation location and conventional facilities requirements Timeline Risk list Summary 2

July Scope Provide 2K cooling to SRF e-Gun and 2K SRF 5-cell Accelerating cavity Provide 3 bar, 5K cooling for heat intercepts for FPC’s and beam line bores. Provide 5K cooling for HTS solenoid inside SRFGun cryostat Provide cooling to high heat load Cold Cathode –Supercritical, single phase, helium cooling 3

July High Level Systems Description: Process Diagram 4 …. SUBCOOLER 2 - 4K WRWR WRWR M M CATHODE HTR SHIELD/TUNER

July High Level Systems Description: SRF-Gun PROCESS SUMMARY 4.8K, 3.8 bar Helium from M-line tap for CeC –Supply transfer line. –Flow to cathode / Subcooler Subcooler (Re-use 912 ERL)  Remove transfer line heat, cool to 4.5K.  Subcooled 4.5K, 3.5 bar to SRFGUN  Return heater, then to 1 atm helium comp.  Mass flow controller 2K COOLING –4.5K, 3.5 bar feeds top fill / bottom fill –2K-4K recovery heat exchanger –Top fill into 2K bath, level control valve –Vapor exits recovery heat exchanger –Back pressure control valve, bath at 23 Torr –Returns to 20 Torr heaters (CeC equipment) –Sub-atmospheric pumps (CeC equipment) Heat Intercept Piping in Gun cryostat –FPC’s, Beam line flanges –Return heaters –Mass flow controllers –HTS Solenoid magnet/Current Leads –Heat Shield cooling –Mass flow controller Small helium compressor (CeC equipment) RHIC WR (warm return to RHIC plant) 5

July High Level Systems Description: CATHODE COOLING PROCESS SUMMARY 4.8K, 3.8 bar Helium from M-line tap (CeC) –Supply transfer line tee off to: –6K, 3.8 bar Flow to cathode –Control valve supply side –Supply to: Flexible Transfer line –Isolation valve –Bayonet interface to cathode cart –Cathode loop: 700W heat load –Return: Flexible Transfer line –Return pressure control / isolation valve –To Common Return heater Subcooler boil-off Cathode cooling return CONTINGENCY (Need LN2 dewar system at RHIC 02:00) Existing CATHODE ERL Change back to LN2 cooled Forced convection boiling heat transfer g/s of flow 3.5 g/s vapor generation at 700W 10% vapor mass fraction for flow boiling 6

July High Level Systems Description: 5-Cell Cryostat PROCESS SUMMARY 4.5K, 3.5 bar subcooler to: 5 CELL CAVITY CRYOSTAT & VALVEBOX –To 5K Intercepts in 5-cell cryostat –To 2K Cooling Loop 2K Cooling Loop –4.5K, 3.5 bar feeds top fill / bottom fill –2K-4K recovery heat exchanger –Top fill into 2K bath, level control valve –Vapor exits recovery heat exchanger –Back pressure control valve, bath at 23 Torr –Returns to 20 Torr heaters (CeC equipment) –Sub-atmospheric pumps (CeC equipment) Heat Intercept piping in 5-CELL cryostat –FPC’s –Beam line flanges –Tuner –Heat shield cooling Return heater Mass flow controllers Small helium compressor (CeC equipment) RHIC WR (warm return to RHIC plant) 7

July High Level Systems Description: Equipment List Supply Transfer Line existing DX-tap for CeC project. Interconnecting VJ lines between subcooler and SRFGun valvebox Interconnecting VJ bundle between Gun valvebox and 5-cell valvebox Subcooler ERL SRFGUN Valve box ERL SRFGUN Cryostat Flexible VJ Helium lines Cathode cooling 20 Torr cold vapor return VJ line to CeC Return heaters Common return heater for subcooler bath / cathode cooling ERL SRF 5-cell Valve box ERL SRF 5-cell Cryostat Return heater 5-cell Tuner/Thermal shield return flow 8

July Parameters: SRF cryostats SRF Gun –2.00K, CW –Static heat leak: 14 W –Dynamic load: 10 W –Heat Intercept/ cooling:  FPC x 2: 0.15 to 0.3 g/s  Beam line Flanges: Cathode side / downstream. 2 x 0.3 g/s –HTS Solenoid cooling: 10 W –HTS current leads: ~ 16 W –Heat shield cooling: ~ 25 W Gun Cathode –Cooling Duty: 700W –Cathode temperature: <90K –Flexible transfer lines retract cathode. –Cooling method: Supercritical helium 3 bar,5K, 6 grams/sec SRF 5-Cell –2.00K, CW –Static heat leak: 21 W –Dynamic load: 5 W [25 W] –Heat Intercept/ cooling:  FPC : 0.15 g/s  Beam line Flanges: 0.15 g/s  Tuner/Shield: 0.1 g/s 9

July Parameters: Cathode Cooling 10 Updated design of cathode: 650W heat dissipation Supercritical Helium Cooling Preliminary analysis shows that this is feasible Detail ANSYS model: Copper temperature profile Lumped model Channel Flow cross section Area m2 Hydraulic Diameter0.0008m Heat transfer Area248cm2 14K, 3.5bar0.0218W/m-K 14K, 3.5bar3.0E-6Pa-s 14K, 3.5bar0.76 Helium Flowrate6g/s Reynolds35700 Nusselt92 Heat transfer coefficient2400W/m2-K LMTD13K

July Parameters: RHIC CRYO PLANT LOADING 4.5K Ref Load Liquefaction load g/s Carnot Work kW Actual Comp. kW Supply line Subcooler load [46 W] SRFgun Cathode cooling SRFgun intercepts cooling HTS solenoid SRF Gun 2K, 39W SRF 5-cell 2K SRF 5-cell intercept cooling Thermal shield All loads returns as liquefaction loads on main RHIC Plant

July Procurements Torr cold vapor return VJ transfer line 2.5”x 4 VJ 2. Cryogenic transfer line, ½”Tx 2”VJ 3. Cryogenic transfer line jumpers between subcooler & valve boxes. 4. Flexible Cryogenic transfer lines set for cathode cooling loop 3.5bar, 5K helium. 5. Return heater for cathode cooling / subcooler boil-off 6. Control system I/O cards (Quantum series) and instrumentation cables, rack components 7. Platform around SRF Cryostats/valveboxes 12

July Relocated Equipment Relocated Subcooler from ERL cryosystem Cryogenic valves from ERL cryosystem Valvebox for SRFGun Valvebox for SRF 5-cell Mass flow controllers and manifold for Intercepts cooling circuits Use/Share of CeC project equipment: 20 Torr Return heaters Sub-atmospheric pumps Small helium compressor 13

July Location in LEReC 14 VALVEBOX SRFGUN SUBCOOLER SEPARATOR/ SRF-5CELL SEPARATOR/ SRF-5CELL SRF 5-cell VALVEBOX SRF 5-cell VALVEBOX LHe supply 20 Torr return CEC 20 Torr Return heaters Tap Existing LHe supply

July C onventional facilities requirements Instrument Air for valve actuators 480 VAC, 3 phase for large return heaters 208 VAC, 1 phase for small return heaters DI water for FPC thermal loops Cable trays: tunnel to racks in trailer/service bldg Utilities for shared equipment from CeC experiment 15

July Timeline 16 Oct 2014Cathode cooling helium lines, Design complete Nov April 2015Cathode cooling helium lines: RFQ, Manufacture, deliver. Jan – Jun 2015:Shutdown for gun modifications and LEReC test preparation (in 912 blockhouse). Apr – Jun 2015Re-install SRFGun into ERL July- Dec 2015Test new cathode with nitrogen cooling Test new Cathode with helium cooling June 2015Supply VJ line, Coldbox interconnects, subcooler jumpers, Design complete. 20 Torr Return VJ Line, Design complete. Return heater, 1 bar helium, Design complete. Nov 2015SRF Gun Valvebox mods/interface, Design and dwgs complete SRF 5-cell Valvebox mods/interface, Design and dwgs complete July Apr 2016Supply VJ line, Coldbox interconnects, subcooler jumpers. RFQ, Manufacture, deliver. 20 Torr Return VJ Line. RFQ, Manufacture, deliver. Return heater, 1 bar helium. RFQ, Manufacture, deliver. Feb 2016SRF Gun Valvebox mods/interfaces, Parts procured. SRF 5-cell Valvebox mods/interfaces, Parts procured.

July Timeline 17 July 2016 – Oct 2016Install SRF 5-cell Cryostat Install SRFGun Valvebox 5-Cell valvebox, Subcooler, Return heater Interface modifications, interconnecting VJ lines Install Instrumentation/controls cables in cable tray Nov Dec 2016Install Supply and 20Torr Return transfer lines Nov 2016Install SRFGun Dec Mar 2017Install VJ transfer lines between SRFGun and valvebox April 2017Warm check out complete CRYOGENICS May 2017Cooldown SRF gun w/RHIC refrigerator

July Risk list 18 RISK / CONTINGENCY Existing CATHODE COOLING ERL Change to LN2 cooled Forced convection boiling heat transfer g/s of flow 3.5 g/s vapor generation at 700W 10% vapor mass fraction for flow boiling

July Summary Re-use existing ERL equipment as much as possible Cathode Cooling with helium will be tested in ERL 912 Fall ‘15 To minimize equipment and installation work no 4.5K return is implemented. All loads are returned as liquefaction load to plant. ~ 0.25 MW higher operating power. 19