QUENCH BEHAVIOUR TEAM ACTIVITIES CERN, 12th October 2015 LMC QUENCH BEHAVIOUR TEAM ACTIVITIES E. Todesco for the QBT CERN, Geneva Switzerland Acknowledgements: HC data of 2015 and 2008 gathered by the MP3 teams Test data gathered by SM18 teams

SUMMARY A Quench Behaviour Team (QBT) has been formed in July 2015 www.cern.ch/qbt Common effort of MSC and MPE groups, and TE dept Main scope Analysis of 2015 hardware commissioning data on training Slow trainer(s) to be replaced in LS2? Outlook for operation in next years Possibility of going to higher energy Correlation to production data Long-term goal: feedback to magnet design for future projects Margin: today 1200 LHC dipoles are operating at 80% of the loadline at 6.5 TeV with a training time at the edge of the shadow of HC

INITIAL BRAINSTORMING The following task have been identified Reproduce in SM18 the behaviour we have seen in the LHC tunnel (test of 3000 series magnets) Further analysis of the 2008 and 2015 hardware commissioning campaign [thanks to MP3s data] An expectation for the next LS’s: same training or different? Identification of weak parts of the 3000 series Secondary quenches: are they reducing training? Are there outliers (in terms of performance) to be replaced in LS2? Correlation to production and test [thanks to production data of PE, SM18 data, …] Identity and memory

INITIAL BRAINSTORMING The following task have been identified (continued) Follow up of flattop quenches during operation Recap the difference between the 1000, 2000 and 3000 series and the procedure we are using today in 180 (4000 series) Correlation of performance during HC and production data What about other magnets? Signs of slow trainer to be replaced? Exploring ways (if any) to speed up training Propose a strategy (if any) for powering above 6.5 TeV before LS2

DATA REMINDER Result I: Result II: 2015 data confirmed that 3000 series magnets quench more than 2000 and 1000 Out of 170 quenches, 140 of 3000 series, 27 of 2000 and 5 of 1000 series Result II: In the 3000 series, the production is not homogeneous Differences are statistically significant Degradation at 3150-3200 (that went on 45) Number quenches per magnet in 3000 series during HC 2015 [G. Willering]

DATA REMINDER Result I: Result II: 2015 confirmed that 3000 series magnets quench more than 2000/1000 series: 140 quenches of 3000 series, 27 of 2000 series and 5 of 1000 series Result II: In the 3000 series, the production is not homogeneous Differences are statistically significant Degradation at 3150-3200 (that went on 45) Number of quenches per magnet in 3000 series with statistical error

2008 VS 2015 What can we expect for the future? Two sectors can be compared: apparent paradox S56 powered at 11100 A 23 quenches in 2008, 16 quenches in 2015 S45 powered to 10300 A 3 quenches in 2008, 10 quenches in 2015 Adding statistical error with two sigma S56: 23±8 in 2008 versus 16±7 in 2015 S34: 3±6 in 2008 versus 10±6 in 2015 Result III: Data are compatible with no degradation and no improvement of training behaviour from 2008 to 2015

2015 VS VIRGIN TRAINING Did 3000 series totally lost memory? In virgin condition: 46% of 3000 series, i.e. 191±20 quenches In 2015: 34% of 3000 series, i.e. 142±19 quenches Result IV: data compatible with a partial but small preservation of memory HC «a bit better» than virgin training Training of virgin magnets during production

TESTS IN SM18 Until now there is a gap between behaviour in SM18 and behaviour in the LHC tunnel We try to bridge this gap Three 3000 series spares available, 3096, 3100 and 3409 3409 only candidate I would dream to have a couple of 3150-3200 magnet to test (what went in 45)

TESTS IN SM18 Is this 3409 representative? This magnet was tested several times  No sign of memory in the first two thermal cycle 0 quenches below 11100 A 3409 already at SM18 on test bench, with BS and no quench antenna We will perform a few more thermal cycles to see if it is really showing loss of memory If yes we will test in 2016 with quench antenna

CONCLUSIONS Quench behaviour team started activities The main questions concern not only the possibility of running LHC at 6.5 TeV and more in the future, but also future projects Analysis of data is difficult – good statistics but we are (often) analysing tails (not for S45) Main directions have been set, help and suggestions are welcome

COMPOSITION B. Auchmann M. Bajko G. De Rijk P. Fessia P. Ferracin P. Hagen S. Le Naour J. C. Perez M. Modena F. Savary R. Schmidt J. Ph. Tock E. Todesco D. Tommasini A. Verweij G. Willering