{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"95df827da5e302afb1ce7fe5930e957bfec01d7b15737d9a42b9b6e06fb38e05","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["c10a59a86d6752943d8827ec43299dbe2eba1215310e024598a76b19fd4d42bd","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"5bfe4be980ad563207689054a6ae7e891fb5d41e9a39cf9e4a406c01c85dbe9e","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"mechanism","assisted_by":[],"external_id":"beams.sc-magnets.training-mechanism","kind":"phenomenon","literature_status":"open","n":"2","parents":[],"plain":"Each premature quench lets the magnet reach a slightly higher current the next time, which suggests that small mechanical events in the coil release heat, but which events and where is not established.","posed_since":"","precise":"$\\mathrm{Nb_3Sn}$ dipoles and quadrupoles operating at $1.1 \\times 10^{5}$ to $1.5 \\times 10^{5}$ G often require tens of training quenches to approach 80 to 90 percent of the conductor short-sample limit. Identify the energy-release events that start training quenches (epoxy cracking, conductor-insulation debonding, stick-slip friction at coil-structure interfaces), their energy spectrum relative to the minimum quench energy of the cable, and a model that predicts the training curve from coil prestress and material properties.","problem_ref":"c10a59a86d6752943d8827ec43299dbe2eba1215310e024598a76b19fd4d42bd","references":"","settled_by":"Acoustic-emission and quench-antenna localization of initiating events across the training of several magnets, matched by a mechanical-thermal model that predicts the training curve of a new magnet before it is tested.","status_note":"Acoustic-emission localization of events during training was reported from 2015 onward; no model predicts training curves (moderate confidence, not rechecked for 2024-2026).","title":"Microscopic origin of quench training in $\\mathrm{Nb_3Sn}$ accelerator magnets","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"d55107ef589009ebf714783441d766bee278169e8937366429d7424e00eb550c","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"fd390bd1032f01c028e0356a4261665906ffe13f5b2df0d3671e1364f84c93bb","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"QENSf7TeDotJVLzg5g_-PNKgYgovr4yJ_hh6KeghC4PHkY268QvZky3o7tfP7wMGyR4TkplRyvnUyln8O5QrBQ"},"schema":"pubphys.envelope/1"},"record_hash":"d55107ef589009ebf714783441d766bee278169e8937366429d7424e00eb550c","leaf_index":2526}