Vishy Ravindranath LCLS-II 2 K Cold Box FDR March 9, 2017 2K Cold Box Process Vishy Ravindranath LCLS-II 2 K Cold Box FDR March 9, 2017

Background- 2K Cold Box Design Changes Outline Background- 2K Cold Box Design Changes Impact of Design Changes on 2K Process & Response (2K Process Model) to 2K Cold Box PDR Recommendation 2K Cold Box P&ID Overview LCLS-II 2 K CBX FDR, Mar 9, 2017

Introduction- First Light & Nominal Beam LCLS-II Linac Operation CRYOPLANT First Light Both Linac Strings supported by 1 Cryoplant Gradient - 14 MV/m 2E10 ≤ Qo ≤ 3E10 2K Cold Box- “High-Flow” Configuration (Max. 2K Mass Flow ~ 200 g/s) Nominal Beam Operations 2 Cryoplants, One cryoplant / LINAC String Gradient - 16 MV/m 2E10 ≤ Qo ≤ 3E10 2K Cold Box- “Low-Flow” Configuration (Max. 2K Mass Flow ~ 130 g/s) Interface Box Functionality: Connection of the Linac strings to a single cryoplant Connection of the upstream Linac to CP-1 and downstream Linac to CP-2 Independent cool-down & warm-up of each Linac String LCLS-II 2 K CBX FDR, Mar 9, 2017

2K Cold Box Design Changes Since PDR (Sept-2016) Conflat Flanges and Removable Pipe Spool Design - PDR Current 2K Cold Box Design- FDR Design Features JLAB Designed U-Tubes (used in CHL-II plant) with Bayonet Connections used for connecting the 2K return transfer line to the suction of CC1 (high-flow) or suction of CC2 (low-flow) To bypass CC-6 (high –flow) and CC-1 (low-flow) requires removing the U-tube external to the 2K cold box. Switching over from High-Flow to Low-Flow does not require working in confined spaces. Design concerns High possibility of helium leaks associated with the large-10” flanges. 2. Schedule concerns –Leak testing and qualifying the flanges requires a minimum of 3 months of R&D. 3. Operation concerns- Switching between the High Flow and Low Flow configuration requires removal and reconnecting of large pipe spools in tight confined spaces

2K Cold Box Process Model- PDR Recommendations Example: Upstream LINAC, E=16 Mv/m, Q0 = 2.7x1010 2K Cold Box Process Model was reviewed during the PDR with the following additional action items Finding: “The 2K cold box will not have a thermal shield. A heat leak analysis has not been performed for the device”. Comment: “Verify calculations to determine if heat leak into the first cold compressor justifies a shield.” Recommendation: “Perform a heat leak analysis on the 2K cold box to ensure that the inlet conditions to the 4.5K cold box can be met.” LCLS-II 2 K CBX FDR, Mar 9, 2017

Response to PDR Comments/Recommendations The heat leak analysis was performed and documented in “LCLSII-4.8-EN-0804 LCLS-II 2K Cold Box Process Analysis ” Thermal Shield is not incorporated for the following reasons: The total heat leak into CC-1 suction line due to conduction and radiation heat load = 11 W By adding a shield, the maximum heat load that can be eliminated is the radiation component ~ 8 W CC1 suction temperature increase due to the radiation heat load of 8 W = 0.02 K Reduction in the 2K cooling capacity due to the 8 W of heat leak = 0.6 % The advantage of providing the thermal shield is small The design complication of incorporating the thermal shield inside the 2K cold box (constrained space) outweighs the small gain in the cooling capacity achieved by adding the thermal shield.

Impact of U-Tubes on the Cold Compressor Suction Temperature and Pressure Increase in CC-1 Suction Temperature- Additional Heat Load Process Location Heat Load Component Heat Load includes 30% design margin [W] 9-1/4” U-Tube Conduction- a. Male Bayonet (QTY: 4) b. Female Bayonet (QTY: 4) 36 Radiation- Jacketed U-Tube 4 Total 40 Change in cold compressor suction conditions: Maximum increase in suction temperature = 0.1 K Maximum increase in suction pressure = 1 mbar Increase in CC-1 Suction Pressure due to U-Tube LCLS-II 2 K CBX FDR, Mar 9, 2017

Impact of U-Tubes on the Cold Compressor Suction Temperature and Pressure ALAT was asked to check and provide maximum 2K flow allowed for the revised inlet pressure and temperature conditions for the selected cold compressor wheel design. HIGH-FLOW LOW-FLOW LCLS-II 2 K CBX FDR, Mar 9, 2017

2K Cold Compressor Vendor Calculation for the Revised Inlet Conditions Ref: ALAT’s Doc: C4118-NT-004 (2), “Mechanical & Electrical Design” Revised Cold Compressor Suction Conditions The selected cold compressor design can provide the following: High Flow Configuration Maximum of 204 g/s Low Flow Configuration - Maximum of 130 g/s LCLS-II 2 K CBX FDR, Mar 9, 2017

Calculated 2K Cold Box Suction Conditions for Required 2K LINAC Operating Conditions a. For LINAC Operation, required 2K cooling capacity (mass flow) to be provided by a single 2K cold box ranges from: 100 g/s to 180 g/s. b. The LINAC 2K Requirements are well within the 2K Cold Compressor Capacity LCLS-II 2 K CBX PDR, Sept 27, 2016

2K Cold Compressor Pump Down Ref: ALAT’s Doc: C4118-NT-004 (2), “Mechanical & Electrical Design” 2K Pump Down Path –High Flow (CC1-CC5) PDR Recommendation: “The pump down path being provided by the vendor is a different approach than Jlab, SNS, and FRIB are employing. Consider capturing this in a risk assessment and developing a back up plan in case commissioning proves difficult.” Response: 1. ALAT has provided a proposed pump down path for the High-Flow and Low-Flow Configurations 2. JLAB will also provide a backup pump down plan based on CHL-II commissioning/operation experiences 2K Pump Down Path –Low Flow (CC2-CC6) LCLS-II 2 K CBX FDR, Mar 9, 2017

2K Cold Box P&ID To 4.5K CBX Clean up return 2. LHe Dewar 4. Safety Reliefs 3. CC Bypass Sub-atmospheric pressure He gas from cryomodules returns to the suction of CCs and is compressed from ~ 27 mbar to 1.2 bar in the 2 K coldbox. The compressed gas returns to 4.5K coldbox through an U-tube. For the test of 2 K CBX with LHe dewar, 4.5K cold vapor from LHe dewar is used to simulate the flow, with a 3 kW heater for controlling the helium temperature in the suction line. A bypass line for the overall CC train is included for 4.5K standby operation mode and pumping down. Safety valves are used for the protection of the 2 K coldbox, CC and process piping. Pressure and temperature measurement are installed at the suction of each CC and on the discharge pipe. A flow meter is installed in the discharge pipe of CCs for flow measurement and controlling of CC. The 2K coldbox provides vacuum insulation for the cryogenic part of CCs and the cryogenic process piping. Clean up and warm up piping are included. Utility piping (Instrument air, cooling water and guard vacuum) are included. Guard Vac. 1. 2K RET From LINAC CM 3 atm He Cooling water Inst. Air

Interfaces –Bayonet Connections Int No. Interface Bayonet Size Component Pressure Rating [psig] Operating Temperature He-501 2K return from Interface Box to CC1 suction 9-1/4” 60.4 4-300 He-502 CC1 discharge to CC2 suction He-503 2K return from Interface Box to CC2 suction He-504 CC5 Discharge 5-3/16” 75.1 He-505 CC6 Suction He-506 CC6 Bypass He-507 30K return from 2K Cold Box to 4K Cold Box He-508 4K vapor supply from LHe storage dewar to CC1 suction 3-1/8” 83.2 LCLS-II 2 K CBX FDR, Mar 9, 2017

Interfaces Int No. Interface Connection ComponentRating [psig] Operating Temperature [K] He-510 Cleanup return ½” pipe weld 150 300 He-511 3 Atm He supply 1” pipe weld GV-512 Guard vacuum 1” pipe weld Vacuum-15 IA-513 Instrument air He-515 Relief Valve Discharge Collector 3” pipe welded 15 4-300 CW-517 Cooling water Supply 2” pipe weld 100 CW-518 Cooling water return ~300 LCLS-II 2 K CBX FDR, Mar 9, 2017

2K Cold Box Control Valves 2K Cold Box consists of six cryogenic control valves: PV41212 (Cold Compressor Bypass Valve): Back-filling of LINAC and for bypassing the cold compressor during 4.5K Standby mode. PV41500/41510/41520 (4.5 K supply from Dewar to 2K Cold Box): to test the 2K cold box/compressors PV41170 & PV41160 (Cold Compressor Discharge valves) LCLS-II 2 K CBX FDR, Mar 9, 2017

2K Cold Box Control Valves 1. Control Valves are sized in accordance with Flow Equations For Sizing Control Valves - ANSI/ISA-75.01.01 (IEC 60534-2-1 Mod)-2007. All valves are fail closed, equal percentage, range-ability of 1:100, angle valve body pattern. The detailed calculations are documented in : Ref: LCLSII-4.8-EN-0802 “LCLS-II Cryoplant Cryogenic Control Valves Sizing” JLAB will procure the control valves and provide them to the 2K cold box manufacturer LCLS-II 2 K CBX FDR, Mar 9, 2017

2K Cold Box Venturi Flow-Meters Flows considered for the sizing are based on CHL-II 2K Cold Compressor Flow Data The flowmeters are sized in accordance with : “Measurement of Fluid flow by means of pressure differential devices-Part 1: ISO 5167-1 (1991)”. The detailed calculations are documented in : “Ref: LCLSII-4.8-EN-0803 LCLS-II Cryoplant Flowmeter Sizing” JLAB will procure the Flow-Meters and provide them to the 2K cold box manufacturer 280 g/s CC mass flow 200 g/s CC5 Discharge Pressure = 1.2 atm CC5 Discharge Temperature 30 K 6K

Utilities 1. Electricity: 480 VAC +/-24V 3 phase – 60Hz +/-1Hz 2. Vacuum guard (For CC and bayonets) Vacuum will be used for the sealing intercept 3. Instrument air For 6 pneumatic control valves Supply pressure of 90 psig 4. Cooling water (For CC and Diffusion Pump) Maximum inlet temperature : 38°C Maximum return temperature : 49°C Maximum flow rate per compressor : 0.75m3/h (3.3 gpm) Pressure drop: < 1bar PDR Recommendations: Consider the use of a closed loop water cooling for the turbine, cold compressors and diffusion pump. Response: There is a secondary closed water loop dedicated for the turbines, cold compressors and diffusion pumps in each cryoplant. P&ID: 79621-0001, “LCLS-II Cooling Water System (For Turbines & Cold Compressors)”

Summary The cold compressor design accommodates the anticipated variation in the heat load. The design & interface requirements for the 2.0 K Cold Box have been clearly identified on the P&ID. PDR Review recommendations have been addressed with further heat load analysis as recommended Detailed supporting calculation documents been developed: Document No. Title Author Status LCLSII-4.8-EN-0802 LCLS-II Cryoplant Cryogenic Control Valves Sizing V. Ravindranath Under Review LCLSII-4.8-EN-0803 LCLS-II Cryoplant Flowmeter Sizing LCLSII-4.8-EN-0804 LCLS-II 2K Cold Box Process Analysis Released 79222-0000 2K Cold Box P&ID JLAB LCLS-II 2 K CBX FDR, Mar 9, 2017

Back-Up LCLS-II 2 K CBX FDR, Mar 9, 2017

LCLS-II Cryomodule Heat Load at 2.0K REF: (1) Tom’s Excel Spread Sheet: “LCLScryoHeat-23Feb2016-FirstLight.xlsx” Tables show the “2.0 K Heat Load” (does not include the heat load on Transfer Lines) The Static Heat Load includes a Design Margin of x 1.30. The uncertainty in the Dynamic Heat Load is in terms of the Cavity Quality Factor A. First Light Configuration E = 14 MV/m, Qo = 2.7E10 E = 14 MV/m, Qo = 2.0E10 E = 14 MV/m, Qo = 3.0E10 Up-stream Down-Stream Total Static [kW] 0.158 0.186 0.344 Dynamic [kW] 1.100 1.200 2.300 1.462 1.608 3.070 0.968 1.083 2.051 Total [kW] 1.258 1.386 2.644 1.620 1.794 3.414 1.126 1.269 2.395 B. Normal Beam Operation E = 16 MV/m, Qo = 2.7E10 E = 16 MV/m, Qo = 2.0E10 E = 16 MV/m, Qo = 3.0E10 Up-stream Down-Stream Total Static [kW] 0.158 0.186 0.344 Dynamic [kW] 1.415 1.615 3.030 1.878 2.146 4.024 1.261 1.464 2.725 Total [kW] 1.573 1.801 3.374 2.036 2.332 4.368 1.419 1.650 3.069 E = 19 MV/m, Qo = 2.0E10 E = 19 MV/m, Qo = 3.0E10   2.569 2.987 5.556 1.717 2.024 3.741 2.727 3.173 5.900 1.875 2.210 4.085

Heat Load on the Transfer Lines- Cryomodule, CDS & Cryoplant Upstream Line A: 89 W Line B: 261 W Downstream Line A: 54 W Line B: 233 W Heat Load includes a design margin of x 1.3. Heat Load on the 2.0 K RETURN LINE-B only contributes to raising the inlet temperature cold compressor suction Ref: LCLSII-4.8-EN-0804 LCLS-II 2K Cold Box Process Analysis