STEAM Simulations for HLLHC Modified RB HEL Circuits

STEAM Simulations for HL-LHC Modified RB HEL Circuits Michał Maciejewski, Matthias Mentink on behalf of the STEAM team

Modified LHC Main Dipole Circuit for the HL-LHC Upgrade ü We have a validated LHC Main Dipole circuit model ü M. Mentink validated an 11 T magnet model in LEDET with measurements: M. Mentink et al, "Analysis of MBHDP 102 CLIQ tests of October 2017 using STEAM-LEDET, " EDMS, Geneva. A B 2

Modified RB – Failure scenarios Reference 1 circuit failure 2 circuits failure Co-simulation of LEDET and PSpice Current Quench integral Final hot spot temperature Peak voltage to ground Hotspot temperature at moment of peak voltage-toground, quench origin at peak-voltage-to-ground turn Peak turn to turn voltage k. A MA 2 s K V Inom 11. 85 15. 1 293 783 166 Iult 12. 80 15. 6 322 974 180 Inom 11. 85 15. 2 299 1038 150 Iult 12. 80 15. 8 327 1217 170 Inom 11. 85 15. 4 305 1457 210 Iult 12. 80 15. 9 332 1600 176 50 63 52 65 53 67 Hotspot temperature at moment of peak voltage-to-ground, quench origin at peak-voltage-to-ground turn was used to determine the operating temperature for HV test SP 109. 3

Modified RB – Cable non-homogeneity RRR = 150 Cu/SC = 1. 25 RRR = 50 Cu/SC = 1. 05 Considered range [2] is - RRR = 100 +/- 50 - Cu/SC = 1. 15 +/-0. 1 An email request has been sent to F. Savary to clarify the conductor specification. [1] 11 T Dipole circuit – powering and protection: https: //edms. cern. ch/document/1764166/0. 9 [2] S. Izquierdo Bermudez, et al: "Quench Protection of the 11 T Nb 3 Sn Dipole for the High Luminosity LHC, " 4 IEEE Transactions on Applied Superconductivity, vol. 28, no. 3, 2018.

Modified LHC Main Dipole Circuit for the HL-LHC Upgrade Status: ü Circuit and magnet failure scenarios were studied in a coupled setting of the modified RB circuit and two electro-thermal models [1, 3] To. Do list: q Update the report following Arjan’s comments IN PROGRESS q Run simulations for a case of 10 ms QH delay in a IN PROGRESS 6/12 DONE q “healthy” magnet q magnet with QH failures q Question from MPE-MI: TO BE STARTED What if during HWC or special powering tests an FPA is triggered for the RB but does not deactivate the 11 T trim PC (GPM masking)? [3] Modified RB circuit quench protection analysis: https: //edms. cern. ch/document/2157321/1 5

The HEL System – SC Magnets Operating Principle (Collimator)* - - - + - - - Magnetic Flux Lines Electron Trajectory Force Directed Radially Inward The Hollow Electron Lens system consists of multiple superconducting magnets for 1. Guiding the hollow beam of electrons: a. (main solenoid, bending solenoid, solenoid after valve, e-gun, CCT) 2. Correcting the field imperfections and fine tune the beam position: a. (4 for the main solenoid, 4 for the main bending, 2 for the e-gun) The aim of this work is to study the protectability of the superconducting circuits. HL-MCF Meeting # 46: Conceptual Design of IFS, CLIQ and K-MOD Feeders+ Quench Study for MCBXF Magnets + Status on HEL Circuits, https: //indico. cern. ch/event/794680/ D. Perini: Status Report on HEL Circuits *A. Bertarelli, et al. Hollow Electron Lens Update, Collimation Upgrade Specification Meeting # 56 6

The HEL System – SC Magnets Status: ü Study of protectability of solenoids [4] To. Do list: q The corrector magnets have been designed. The following data was requested: q Magnet geometry, cable parameters, operating current, inductance q Run QLASA simulations for solenoids to prove that EE is needed; q Study quench protection of busbars for the main solenoids; q Supervise Youssef on creation of a notebook to calculate the EE protection (MIIts curve calculation, Metrosil); q For CHATS on 09. 07, prepare: q a presentation q a paper for Cryogenics (optional) [4] Protection of magnet circuits for hollow e-lens: https: //indico. cern. ch/event/814368/ 7