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TE/MPE-PE Section Meeting, 15.04.2014. BLM Threshold Working Group. BLM Thresholds Working Group. Ionization chambers filled with N 2 at 1.5 kV between anode and cathode. Thresholds (mostly) prevent magnets from quenching and (for loss duration > 320 µs) from damage. Up to now 2 WGs.
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TE/MPE-PE Section Meeting, 15.04.2014 BLM Threshold Working Group
BLM Thresholds Working Group • Ionization chambers filled with N2 at 1.5 kV between anode and cathode. • Thresholds (mostly) prevent magnets from quenching and (for loss duration > 320 µs) from damage.
Up to now 2 WGs • The BLM Thresholds WG • discussed requests for changes to master thresholds, monitor factors, or sensitivity-ranges; study of noise levels and need for filtering; replacement of monitor types; cross-talk; connection to BIS, production and deployment of thresholds; etc. • issued ECRs to document changes to master thresholds. • The Quench Test • planned, organized, and analyzed controlled beam-loss events to • improve the understanding of quench levels in LHC SC magnets; • validate and improve the simulation approach and numerical tools. Analysis Preparation Collimation FBCM BPM ELQA BLM QPS MAD-X QP3 LIBD FLUKA MAD-X MPP 6 Strategy Mtgs 4 MDs FLUKA Deposited energy SixTrack OP 4 successful quench tests Min. quench energy QPS QP3/THEA RF
Merging the WGs • Intention: • Direct the momentum and experience from quench-test analysis to improved BLM thresholds. • Provide a global view on technical and analysis aspects of BLM thresholds: • technical aspects: generation of threshold tables, noise, filtering, sensitivity ranges, issuing of ECRs, etc. • analysis aspects: simulation of quench levels and damage levels in affected equipment, study of events and quench-tests. • All responsible teams are involved in the working group. • Collimation, injection, beam dump, warm magnets, cold magnets, FLUKA team, etc.. • Responsible teams share operational experience, provide analyses, propose threshold changes.
Next Steps 2014 • Case study MQ BLM family 1: • Define relevant beam-loss scenarios per time range and energy level. • Predict quench levels based on quench-test analyses. • Compare to previous models, beam-loss scenarios, and ad-hoc scaling. • Present new quench-level tables to MPP. • Review of BLM families and beam-loss scenarios. • Compute new tables of quench levels and compare in detail to previous assumptions. • Review cross talk, noise levels, sensitivity range, monitor types, monitor placement in specific locations and their implication on thresholds and local protection. • Present threshold-update strategy for approval to LMC. • Validate threshold generation and deployment. • Deploy new thresholds.