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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 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