Lambda plates for WP 3 Functional Technical Specifications

Lambda plates for WP 3: Functional & Technical Specifications Y. Leclercq, S. Spathopoulos*, F. Crisci, J. B Deschamps, S. Donche for WP 3 Engineering Design Review of the Lambda Plate 13. 04. 2021

General overview § § Two lambda plates, one for DFX-IT and one for DFM-D 2 interface located at 89. 5 m and 140 m from IP respectively. Main functions: § § Leaktight separation between DFX/DFM saturated helium and IT/D 2 superfluid helium volumes. Electrical continuity ensured between conductors of the adjastent cryogenic volumes EDMS 2507629 Mainly focused during that presentation Lambda Plate Engineering Design Review – 13. 04. 2021 2

Functional specifications § Lambda plate assembly components: § § Support plate made of st. steel Two thermal insulation plates Plug subassemblies Main requirements § Not influencing quench detection system and quench propagation velocity § Ensure cable-to-ground + cable-to-cable electrical insulation over lifetime § Leak tightness between cryogenic volumes and heliuminsulation volumes Comply with applicable pressure vessel standards Mechanical integrity of elements over lifetime § § - Electrical - Thermal & insulation vacuum - Mechanical 18 k. A plug configuration 2 k. A plug configuration 3

DFX-IT (λΧ) - Electrical requirements Circuit Round [mm] 18 k. A Ø 13 2 k. A Ø 7 21 LHC 02 Unit § λΧ contains 19 cables of 2 types § 7 x 18 k. A and 12 x 2 k. A round cables are passing through the LP Type of strands [-] 34 LHC 01 § Electrical Insulation requirement (cables to cables & to ground) Trans. Pitch [mm] 150 20. 7 Section surface SC/Cu [mm 2] 11. 4/84 3. 8/20. 7 Ø multi-filamentary copper core [mm] 10. 9 4. 9 Minimum bending radius [mm] 125 External envelope 10 k. V during 30 s. Criteria : Maximum Leakage current 10 u. A Illustration of section DFX-DCM Lambda Plate ʎX Cable properties (A. Ballarino, J. Fleiter “Busbar_for_WP 6 a_Inner_triplets”, EDMS 2376444) Unit Triplets Trims D 1 Correct ors [-] MQXF MBXF MCBXF [k. A] 17. 5 7. 0 13. 0 1. 73 Nb of branches [-] 2 3 2 12 Conductor material [-] Nb. Ti Conductor model, see Table 2. [-] Round 18 k. A 2 k. A Circuit Corresponding magnet reference Operationnal current [-] Busbar properties (E. Todesco “HL-LHC WP 3 Bus Bars technical specification and conceptual lay out”, EDMS 2029211) x 6 Not updated MCF dwg Courtesy S. Yammine 4

DFX-IT (λΧ) - Cryogenic & thermal requirements § Lambda plate separates two cryogenic volumes: Cold powering (DFX/DFM) and Magnet side (IT/D 2) DFX IT (DCM) Design Pressure acc. To PED Category acc. To PED Test Pressure acc. To PED Operational pressure range Design number of pressure cycles Nominal pressure Fluid in nominal operation Nominal temperature Maximum leak rate level through Lambda Plate* Maximum static heat loads to 1. 9 K Thermal cycle over lifetime PS = 3. 5 bara PS = 20 bara Liquid Helium ≤ 4. 5 K Superfluid Helium ≤ 2. 17 K Magnet side Cold powering [bara] [-] [bara] (IT/D 2) 20 IV Acc. To PED 0 to 20 (DFX/DFM) 3. 5 III Acc. To PED 0 to 20 [-] 100 Unit [bara] [-] 1. 5 Superfluid He Liquid He ≤ 2. 17 K ≤ 4. 5 K Cryogenic volume properties Unit ʎX ʎM [mbar. l. s-1] 10 -4 [W] 15 7 [-] 50 50 Cool Down design requirements [-] Warm up design requirements [-] Instantaneous immersion in LN 2 from Ambient Temperature Natural convection in air from LN 2 temperature *measured at RT with Helium as tracer gas following method A 1 from EN 1779. Cryogenic design specifications Lambda Plate Engineering Design Review – 13. 04. 2021 5

DFX-IT (λΧ) - Mechanical, Integration/Interfaces & Safety requirements Mechanical Lambda plates shall comply with: § § Proven resistance to pressures over cycles and conditions already defined Radiation levels over lifetime of machine Lorentz forces PED based on material choice for pressurized envelope Typical forces between cables @ 100 mm Between two 18 k. A cables Between two 2 k. A cables Between one 2 k. A and 18 k. A cables Unit Value [N/m] 650 8 72 Lorentz forces (Fleiter “DFH, cables, splices and instrumentation”, DFH DDR, Indico 925877) Maximum non flexible length of the cable on either side of the plug Minimum bending radius from the end of the rigid part of the cable Mechanical plug flexibility Unit 18 k. A model 2 k. A model [mm] 200 150 [mm] 150 100 Integration & Interfaces Both LP at DFX-D 2 and DCM-IT interfaces shall withstand radiation levels of 50 k. Gy and 200 k. Gy, respectively. Dose @ 3000 fb-1 Neutron Fluence Unit [k. Gy] [cm-2] ʎX 50 2. 1014 ʎM 200 2. 1014 Radiation levels (WP 10, G. Lerner “HL-LHC radiation levels on the IT cold diode in the LSS of IP 1” EDMS 2201836) (G. Lerner “Radiation Level Specifications for HL-LHC” link) Safety considerations § LP pressurised vessels covered by the PED. § Electrical insulating materials + cables not covered by the PED -> the integrity with respect to pressure shall be demonstrated and the qualification agreed with HSE. Lambda Plate Engineering Design Review – 13. 04. 2021 6

Technical specifications Design § Comply with the level of performance, the interfaces and all requirements specified already § Verified by calculations acc. to PED or sound engineering practice where standards are not applicable. Procurement of single parts § Material requirement § § § Cern safety instruction IS 41 (plastic and non-metallic materials) Memo on allowable cobalt content (EDMS 2411822) Material certificate & traceability Compliant with PED for stainless steel envelopes Cleanliness : compliant with ISO 23208 Quality assurance and documentation § § Material certificate Certification of use for busbars Assembly of series at CERN § § Performed by qualified operators on qualified processes Activities: § § § Soldering Gluing Cleaning Testing Packing Lambda Plate Engineering Design Review – 13. 04. 2021 7

Technical specifications (see MIP presentation) Quality control requirements (see MIP presentation) § § § Thermal cycle : 100 % of finished plugs shall be thermally cycled in LN 2 Pressure test of finished plugs to 30 bar Dimensional controls : measure and report Leak tightness of finished plugs Electrical insulation test : 10 k. V Maximum leakage current 10 u. A. Main documentations to be uploaded to MTF § Material Certificates § MIP mentioning operators and associated qualifications § Pressure test report § Dimensional controls § Leak test report after thermal cycles and pressure test report § Electrical test report Lambda Plate Engineering Design Review – 13. 04. 2021 8

Conclusion § § The functional and technical specifications of the lambda plates are presented in the EDMS 2507629 document (status : in review) Individual items, mechanical parts and cables shall be supplied with requested documentation MTF structure shall contain all indicated documentation QC tests are defined Lambda Plate Engineering Design Review – 13. 04. 2021 9