{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"41adb4519b1fd4ab25da615d9ecd4d5a08887bbc4d8beb1654981123b04c5664","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b","ddbcf58dba29987b52040846a8919e7d28820e1dd68c04906a50239e4f63fa1e"],"salt":"458057b257285014fddbcf1f186c2683ca7abe01488b1c8f6222c4066b38a705","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"beams.microbunching-fel.transform-limited","kind":"well-posed","literature_status":"open","n":"2","parents":[],"plain":"The best possible laser pulse has the narrowest color range allowed by its duration. Whether hard X-ray lasers can reach that limit shot after shot is open.","posed_since":"","precise":"Determine whether a seeded or cavity-based XFEL at photon energy $> 5\\ \\mathrm{keV}$ can deliver pulses with time-bandwidth product within 1.5 times the transform limit and pulse-to-pulse energy fluctuation below a few percent, given shot noise and microbunching in the electron beam.","problem_ref":"ddbcf58dba29987b52040846a8919e7d28820e1dd68c04906a50239e4f63fa1e","references":"","settled_by":"Single-shot spectral and temporal measurements of a hard X-ray FEL meeting the stated criteria over many shots.","status_note":"","title":"Can XFELs produce stable transform-limited hard X-ray pulses?","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"cd46148f959381c60765d4e7c436b085e6aae9f50d4678d11a37f4e94fb05de5","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"1c17a67937bbd57175066bfde75af087767a0897e38c02cdf25ce5d35e24bd64","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"j2DOC5VcmizXqLMGCPLxVLrdfxHFgZDliXQ0oapqkVNABqdHOvFBjUDgw_M2yDxNWWeclp84xxRRkJL2MYuwDg"},"schema":"pubphys.envelope/1"},"record_hash":"cd46148f959381c60765d4e7c436b085e6aae9f50d4678d11a37f4e94fb05de5","leaf_index":2486}