MBHSP109 and MBHSP107 29 May 2019, Gerard Willering

SP109 test goal and program Magnet not connected for powering. Only HV test between quench heaters, coil and ground Each QH seperately connected, so HV test can be done for each heater strip seperately. Use HFM test station Connector in He gas for QH has been replaced. Test station tested at 5 kV in air between QH leads, Leads and ground. Goal 1: Find in a non-destructive way the leakage current up to specified levels. In all cases do a charge/discharge test between each QH circuit and ground. 300 K – 500 V 1.9 K – 3.4 kV Goal 2: Find the coil limit Find in a non-destructive way the leakage current up to specified levels. After meeting comment: Discuss in more detail with Felix and Jan. In principle a few temperature levels between 80 and 300 K, with 1.5 kV at 200 K as reference level. Three connectors. Possible limiting point connector in pizzabox Note that only 1 cool down and warm up is foreseen and that we have to prioritize the tests that are important due to a very busy schedule in June. MBHSP109 test program

Test program SP107 Recap SP109 mid plane segments: Main goal: Verify long term behavior, looking at performance indicators. Recap SP109 mid plane segments: Each thermal cycle: VI curve shifted, coil performance limit reduced. Following many current cycles: no change Following quenches: no change Following high QI tests: small reduction of coil performance limit above 16.5 MA2s or about 320 to 340 K. CD 1 CD 2 CD 3 CD 4 -3 % MBHSP109 test program

SP107 history Short training campaign Thermal cycle Not pushed beyond ultimate No V-I curves No particular issues revealed with this magnet. The only measured performance indicators are: Quench at 4.5 K at 10 A/s RR studies to coil limit at 200, 300 and 400 A/s at 1.9 K. 4.5 K limit of 12.3 kA would suggest a 1.9 K limit of about 500 A beyond ultimate current. Thermal cycling, see https://indico.cern.ch/event/820655/ by Jan Petrik After SM18 tests, 10 thermal cycles in Liquid Nitrogen were performed in Cryolab 300 K to 80 K, delta Tmax = 78 K. Dielectric strength tests performed at 660 V each cycle. MBHSP109 test program

Test plan for SP107 Impact of thermal cycles is a main goal. SP107 powering tests performed in HFM test station SP109 powering tests performed in Long test station (Larger and less controlled temperature gradients) Suggestion Put SP107 first in HFM station, powering test, perform a second cool down, powering tests . Then put it in the Long test station for a thermal cycle later to study a different cool down and thermal cycle gradients. In this way we can conclude more on the impact of different type of gradients, and possibly link the SP109 degradation to the test station. Note that this would delay MQXFS6 second tests and increase load on test station. Focus on performance indicators, so each cool down: Start with 1.9 K training to 12.85 kA 4.5 K verification and V-I measurement up to coil limit of midplane turns 1.9 K RR studies (verify with earlier results) 1.9 K V-I measurements High QI studies at end of last cool down. MBHSP109 test program

SP107 test program in more detail HFM test station available 17th June (after test of SP109) Standard HV tests (1 kV QH-ground-coil) Cool down, gradient < 50 K 1.9 K: training to 12.85 kA 4.5 K: training (verification of coil limit) 4.5 K: V-I + holding current 1.9 K: ramp rate studies for comparison Thermal cycle (should start by June 28th) 4.5 K: V-I verification 4.5 K: training and verification of coil limit (more difficult to compare retraining with first cool down) 4.5 K: V-I 1.9 K: training to 12.85 kA (or do we want to go higher?) Warm up (test station available for MQXFS6 by July 15th) Depending of results and resources, repeat for a test in the Long test station (or try a high thermal gradient in the HFM test station) MBHSP109 test program

Overall Schedule Line up of Connection cryostat SP107 SP109 250 A trim leads Cryotec LINK test MCBXF MQXFS4 MQXFS6 Not to forget cavities tests that use the same helium resource. MBHSP109 test program