DIPOLE QUENCH HEATERS TEST PROPOSAL Marta Bajko Zinur

DIPOLE QUENCH HEATERS TEST PROPOSAL Marta Bajko, Zinur Charifoulline, Sandrine Le Naour, Andrea Musso, Hervé Prin, Jens Steckert, Arjan Verweij, Gerard Willering MSC-Technical meeting, July 3 rd 2014 Cryo-Magnet Coordination & MP 3

Summary • Short introduction (some history…) • Scope and development of the test • Candidate magnet • Test development and schedule proposal • References • Conclusions July 2014 Andrea Musso 2

Introduction (some history…) • Quench heater failures were a main subject during the whole production of the dipoles at industry’s premises • Most of the issues were related to assembly at firm 2 • Several reports were issued to better understand the phenomenon and to show the assembly differences between manufacturers. • Quench heaters were produced by 3 different firms, with the following distribution CICOREL 45% CIV 44% Thanks to EDMS Support for fast reaction!! AXON 10% • The design of the item was never tested at fatigue • A monitoring system was developed in order to detect failures at early stage July 2014 Andrea Musso 3

Scope of the test MP 3 Committee motivation for the test: • “To assess fatigue issues on a relevant number of quench heaters, approaching as close as possible the conditions during a real quench. ” • “To assess the functioning and reproducibility of the DQHSU Quench Heater monitoring system and the data analysis software. ” Engineering Technical Note being released: “MP 3 Recommendation on the Testing of fatigue of MB Quench Heaters and the monitoring system” July 2014 Andrea Musso 4

Development of the test • To perform the test: • • The magnet is installed on a bench and cooled down at SM 18 The magnet is NOT powered (NCR 1060444, Breakdown at 1900 V) The new QPS diagnostic and analysis tool is connected Nominal voltage and current discharge will be used In the magnet there are 16 quench heater’s strips; we propose to perform 500 discharges on each of them at the same time. The needed time shall be 10 -15 minutes each discharge 90 h<t<125 h LHC: 25 years of operation, 10 discharges per year (real maximum)=250 discharges. To obtain a factor 2 (i. e. 500 discharges) the manpower needed is roughly 1 additional week for 1 person July 2014 Andrea Musso 5

Candidate magnet • Considering that most of the issues related to manufacturing were related to firm 2, we propose to candidate a magnet from firm 1 or 3 • We need to choose a magnet that has to be fully dismantled for repair, to minimize impact on spare availability and recovery after the test • There is only one magnet that corresponds to such criteria: HCLBBR_000 -CR 001007 R r NC o j a m e to u d est d w e o l l t n e isma n (i. e. th d y l l Axo e fu …? ) b s g i n o i r t e h r t s n no it ha nufactu a e h s t a a etter any c heater m 07: b ( n 0 i s 1 : c s le ti e pro : Quench HC) tatis Dipo s h T g i s L b • e con on in the not give h T • lati will u y p l o n p o gnet a M • 1 July 2014 Andrea Musso 6

Conclusions The test: • • Will permit to verify the QPS system Will permit to verify the tool analysis during discharge Will give statistic with 8000 discharges Will give information about design limits (fatigue test) • Will be performed on a quench heater manufactured by Axon, that represents a small population in the LHC Known risks: • A quench heater failure might damage a coil if the discharge burns the insulation layers – The magnet needs anyway to be dismantled and its coils need a deep check in order to solve the breakdown non conformity July 2014 Andrea Musso 7

References If you like to read: • M. Bajko, G. Berard, G. Rolando, G. Molinari, “Report on Quench Heater failures”, EDMS 889445, ATMCS-Technical note, 2008 • A. Musso, “Quench heater inspection and assembly procedure at cold mass assemblers”, EDMS 593927, AT-MAS Technical Note • F. Rodriguez-Mateos, P. Pugnat, S. Sanfilippo, R. Schmidt, A. Siemko, F. Sonnemann, “Quench Heater Experiments on the LHC Main Superconducting Magnets”, LHC-Project-Report-418, 2000 July 2014 Andrea Musso 8

Than ks fo July 2014 r you r atte Andrea Musso ntion … 9