{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"35386770229fa7b6961bf928afae3730f4f731c5e5ea89c1f361ed3234e5a915","created":"2026-10-03T07:17:56Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"77a7311ee1eafe3c617a28de2e4bf997dd721bec151a218426c5ec1438566c2f","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":"1","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":"Nb3Sn dipoles and quadrupoles operating at 1.1e5 to 1.5e5 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":null,"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 Nb3Sn accelerator magnets","topic_ref":"a83e07dd68407ac5bcfad93a1a605a4cf0470772a34c776e66dd884c34f68340"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"c10a59a86d6752943d8827ec43299dbe2eba1215310e024598a76b19fd4d42bd","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"35d9af687561bfccf8609c6f6b86352bf9614fb60f66be982667d88d65d603b0","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"256SXgs-oFteBNGWInohte2bGr9mKHgMFllAw13Et9o7dMcGsvfpag8rVkcj6yJpufpBnb48UdlLpnmOljscAg"},"schema":"pubphys.envelope/1"},"record_hash":"c10a59a86d6752943d8827ec43299dbe2eba1215310e024598a76b19fd4d42bd","leaf_index":698}