{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.topic/1","content_sha256":"d5ae585a91fe1d5094c08d0f0082b5df35f7a54af5f7fd9311a3cacfb4763885","created":"2026-10-03T07:17:50Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":[],"salt":"6d516d8a980118ca565f1905c0469efc772d82e1dd9f49aedf3bfdbd96a154e3","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"topic"},"content":{"external_id":"beams.rf-breakdown","field":"beams","n":"1","review_cite":"A. Grudiev, S. Calatroni, W. Wuensch, New local field quantity describing the high gradient limit of accelerating structures, Physical Review Special Topics - Accelerators and Beams, 2009","review_link":"https://doi.org/10.1103/PhysRevSTAB.12.102001","review_verified":"true","summary":"Copper accelerating structures can hold only so strong an electric field before sparks (breakdowns) jump across the vacuum and spoil the beam. Nobody can yet predict from basic physics where that limit lies.","title":"Vacuum RF breakdown in normal-conducting structures","topic_ref":null,"why":"The breakdown limit sets the length, and so the cost, of any normal-conducting linear collider, compact linac or muon cooling channel."},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"29c52025bad0f3bb40505db955939f35befc6ea9256f5e4972142fac9de7c602","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"8177b377ee92608745ef613152545ea31af014fac799e2c69dcbc189e73b0c44","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"JGuwn_8uhNiqUqZ32hPoGWGKRIYEKivehyD68-VfMlyEF8kxmzBUOLYDVRw5Kz7z7STSqqYWwf2dLdbtzmkGDg"},"schema":"pubphys.envelope/1"},"record_hash":"29c52025bad0f3bb40505db955939f35befc6ea9256f5e4972142fac9de7c602","leaf_index":73}