{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2025:Q3SFWEC2WMDIHKDXRNEWN3QGGZ","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"371aec51c324df50bf71ebb649b15f00f82367358b013ced0fb094fa04e56874","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"physics.acc-ph","submitted_at":"2025-08-12T21:38:25Z","title_canon_sha256":"de951508f4777bb5119e7557ecc7150b6d143796d3e4c25555263dd52d0ff585"},"schema_version":"1.0","source":{"id":"2508.09357","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2508.09357","created_at":"2026-07-05T11:53:13Z"},{"alias_kind":"arxiv_version","alias_value":"2508.09357v1","created_at":"2026-07-05T11:53:13Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2508.09357","created_at":"2026-07-05T11:53:13Z"},{"alias_kind":"pith_short_12","alias_value":"Q3SFWEC2WMDI","created_at":"2026-07-05T11:53:13Z"},{"alias_kind":"pith_short_16","alias_value":"Q3SFWEC2WMDIHKDX","created_at":"2026-07-05T11:53:13Z"},{"alias_kind":"pith_short_8","alias_value":"Q3SFWEC2","created_at":"2026-07-05T11:53:13Z"}],"graph_snapshots":[{"event_id":"sha256:4176f97d161a0fe677eb38ca2f70b15a9abe123ca5ab1af5d723e96941eb788a","target":"graph","created_at":"2026-07-05T11:53:13Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"integrity":{"available":true,"clean":true,"detectors_run":[],"endpoint":"/pith/2508.09357/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"The temporal resolution of MeV ultrafast electron diffraction (UED) is fundamentally constrained by the electron bunch length at the sample, motivating the development of new electron sources capable of producing femtosecond scale bunches. In this work, we propose a multicell RF photogun that has a tailored phase velocity profile to generate 5 to 15 fs rms MeV electron bunches directly from the electron gun, eliminating the need for downstream compression. This approach achieves comparable performance to conventional one and a half cell photoguns with downstream compression, while reducing sys","authors_text":"Alexander Dietrich, Alexandre Trisorio, Carl Beard, Carlo Vicario, Cezary Sydlo, David Alesini, Eduard Prat, Hans-H. Braun, Mike Seidel, Paolo Craievich, Rasmus Ischebeck, Riccardo Zennaro, Thomas Geoffrey Lucas, Zheqiao Geng","cross_cats":[],"headline":"","license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"physics.acc-ph","submitted_at":"2025-08-12T21:38:25Z","title":"Femtosecond-Scale MeV-UED Beamline Using a Stand-Alone Multi-Cell RF Photogun"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2508.09357","kind":"arxiv","version":1},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:fc3395cd630dfe98252b383ed24b2c3a8d41fb436cd3cbb4c56ec0c3bd4930ca","target":"record","created_at":"2026-07-05T11:53:13Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"371aec51c324df50bf71ebb649b15f00f82367358b013ced0fb094fa04e56874","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"physics.acc-ph","submitted_at":"2025-08-12T21:38:25Z","title_canon_sha256":"de951508f4777bb5119e7557ecc7150b6d143796d3e4c25555263dd52d0ff585"},"schema_version":"1.0","source":{"id":"2508.09357","kind":"arxiv","version":1}},"canonical_sha256":"86e45b105ab30683a8778b4966ee063662ef822f631c61e99a30f1227b518d76","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"86e45b105ab30683a8778b4966ee063662ef822f631c61e99a30f1227b518d76","first_computed_at":"2026-07-05T11:53:13.291023Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T11:53:13.291023Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"PFXmJinhoNdq+Bd85O/9CoxB0yqHexq6pYFI0So7btFkMHGt7dWVsfgQgpzFPg5k/VP2XVt10SOb6ByA8UZsCA==","signature_status":"signed_v1","signed_at":"2026-07-05T11:53:13.291530Z","signed_message":"canonical_sha256_bytes"},"source_id":"2508.09357","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:fc3395cd630dfe98252b383ed24b2c3a8d41fb436cd3cbb4c56ec0c3bd4930ca","sha256:4176f97d161a0fe677eb38ca2f70b15a9abe123ca5ab1af5d723e96941eb788a"],"state_sha256":"d7f2d59df25ad85136fa490b2682dd815bcc8fb48a971f495765a4a91729fb48"}