{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"3410febe39f96bda7f814cfb55b4635f5a99aeacf5616fc7b9ddc161c8f985d4","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["58464bb5aad78603c230dcdcffe3735d686418908fcdcb1c899a41d1a34301e3","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"24529d5951b0637c197b82c069093cd3b69465054b1d70d476860d633660df8c","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"mechanism","assisted_by":[],"external_id":"beams.collective-instabilities.dust-release-mechanism","kind":"phenomenon","literature_status":"partially-resolved","n":"2","parents":[],"plain":"Micron-sized dust grains fall from the LHC vacuum chamber walls into the beam and cause sudden losses that can quench magnets; what makes them detach is unclear.","posed_since":"2010","precise":"Fast loss events in the LHC (called UFOs, unidentified falling objects) last of order $10^{-3}$ s and are modeled as micron-scale dust grains entering the proton beam, being ionized and repelled; this dust-beam dynamics was analyzed in 2020. Determine the release mechanism (electrostatic detachment driven by beam-induced charging or electron cloud, mechanical vibration, magnetic forces on ferromagnetic grains) and predict the event rate versus beam intensity, bunch spacing and cumulative beam time.","problem_ref":"58464bb5aad78603c230dcdcffe3735d686418908fcdcb1c899a41d1a34301e3","references":"","settled_by":"Laboratory release tests on beam-screen surfaces under electron bombardment and electric field that reproduce the measured dependence of the event rate on intensity and conditioning time.","status_note":"Dust-beam interaction dynamics were modeled and matched to loss signals in 2020 (Lindstrom et al., https://doi.org/10.1103/PhysRevAccelBeams.23.124501); the release step is not established.","title":"Release mechanism of dust grains causing fast LHC beam losses","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"52b7c10de0a21d8b859a6854843e98627ffe2667c5d237d88a589b41a1bdc668","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"5579faf48b1f9771005b3fd97d7a0f4bbbb11dea9ad17a9b86131b3bed6678c2","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"o-hJ5BikU6l3rsBWSDc8gKZTG4ZcHo8Cb2QCOs-aHV37-feuOUKZm4V06v11CLGl6TEvRuC7nKt4cUCiTNgqBQ"},"schema":"pubphys.envelope/1"},"record_hash":"52b7c10de0a21d8b859a6854843e98627ffe2667c5d237d88a589b41a1bdc668","leaf_index":2468}