{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2020:PHRKRV6ESSHPUIF2L5Z5YZO6DO","short_pith_number":"pith:PHRKRV6E","canonical_record":{"source":{"id":"2004.08034","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"physics.acc-ph","submitted_at":"2020-04-17T02:10:26Z","cross_cats_sorted":[],"title_canon_sha256":"dbcb05dbc835aa152019a4a371a302cae80eda20a2aca06611ba5d7f85717139","abstract_canon_sha256":"000d8b05a060c444136c40c6dca13b2073e5a164a7292050211ae5c9c1e9231a"},"schema_version":"1.0"},"canonical_sha256":"79e2a8d7c4948efa20ba5f73dc65de1b93f1bcfa13425daf5b69b72dadd893c7","source":{"kind":"arxiv","id":"2004.08034","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2004.08034","created_at":"2026-07-05T01:23:06Z"},{"alias_kind":"arxiv_version","alias_value":"2004.08034v1","created_at":"2026-07-05T01:23:06Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2004.08034","created_at":"2026-07-05T01:23:06Z"},{"alias_kind":"pith_short_12","alias_value":"PHRKRV6ESSHP","created_at":"2026-07-05T01:23:06Z"},{"alias_kind":"pith_short_16","alias_value":"PHRKRV6ESSHPUIF2","created_at":"2026-07-05T01:23:06Z"},{"alias_kind":"pith_short_8","alias_value":"PHRKRV6E","created_at":"2026-07-05T01:23:06Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2020:PHRKRV6ESSHPUIF2L5Z5YZO6DO","target":"record","payload":{"canonical_record":{"source":{"id":"2004.08034","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"physics.acc-ph","submitted_at":"2020-04-17T02:10:26Z","cross_cats_sorted":[],"title_canon_sha256":"dbcb05dbc835aa152019a4a371a302cae80eda20a2aca06611ba5d7f85717139","abstract_canon_sha256":"000d8b05a060c444136c40c6dca13b2073e5a164a7292050211ae5c9c1e9231a"},"schema_version":"1.0"},"canonical_sha256":"79e2a8d7c4948efa20ba5f73dc65de1b93f1bcfa13425daf5b69b72dadd893c7","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T01:23:06.030409Z","signature_b64":"MKbLRWzeJUNZA0TSfsAfI3tLpwZ2pOGH7CR6NwKb9v8TDgW45bZMNBU4yHVmL+X4pxWHVCOpwiV0ZpkCbOFRDQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"79e2a8d7c4948efa20ba5f73dc65de1b93f1bcfa13425daf5b69b72dadd893c7","last_reissued_at":"2026-07-05T01:23:06.029891Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T01:23:06.029891Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2004.08034","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T01:23:06Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"jdjK9idtEnBUPjIBx9/6RhQwfFippB9mYgqUeLZJCRVFj6CLW8okPHrC+st51SFsPLZ9rfVjwG6n21oI4n5gAA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-18T21:51:58.952271Z"},"content_sha256":"4c9dd6bb937eb21afc84145e1e781eaef319a2ce5b60f1ba2c45e466f6fe8dff","schema_version":"1.0","event_id":"sha256:4c9dd6bb937eb21afc84145e1e781eaef319a2ce5b60f1ba2c45e466f6fe8dff"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2020:PHRKRV6ESSHPUIF2L5Z5YZO6DO","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"The Role of Low Intrinsic Emittance in Modern Photoinjector Brightness","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":[],"primary_cat":"physics.acc-ph","authors_text":"Bruce M. Dunham, Christopher M. Pierce, Colwyn Gulliford, Edmond Lu, Ivan V. Bazarov, Jared M. Maxson, Matthew B. Andorf, Matthew Gordon, Nora P. Norvell, Tor O. Raubenheimer, Young-Kee Kim","submitted_at":"2020-04-17T02:10:26Z","abstract_excerpt":"Reducing the intrinsic emittance of photocathodes is one of the most promising routes to improving the brightness of electron sources. However, when emittance growth occurs during beam transport (for example, due to space-charge), it is possible that this emittance growth overwhelms the contribution of the photocathode and, thus, in this case source emittance improvements are not beneficial. Using multi-objective genetic optimization, we investigate the role intrinsic emittance plays in determining the final emittance of several space-charge dominated photoinjectors, including those for high r"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2004.08034","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2004.08034/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T01:23:06Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"CIf1BhTMlQxkq8jyGR7eK1zfARrYydw2KLAJq5+xteoTJszy5MYg5xUte3DkCy62q8A2kMtqFX5s/1r/7txKAQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-18T21:51:58.952643Z"},"content_sha256":"81de1c96cce9ef18ab1f1004972406d8c41d30d000f90ac78c68ad438db25951","schema_version":"1.0","event_id":"sha256:81de1c96cce9ef18ab1f1004972406d8c41d30d000f90ac78c68ad438db25951"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/PHRKRV6ESSHPUIF2L5Z5YZO6DO/bundle.json","state_url":"https://pith.science/pith/PHRKRV6ESSHPUIF2L5Z5YZO6DO/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/PHRKRV6ESSHPUIF2L5Z5YZO6DO/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-08-18T21:51:58Z","links":{"resolver":"https://pith.science/pith/PHRKRV6ESSHPUIF2L5Z5YZO6DO","bundle":"https://pith.science/pith/PHRKRV6ESSHPUIF2L5Z5YZO6DO/bundle.json","state":"https://pith.science/pith/PHRKRV6ESSHPUIF2L5Z5YZO6DO/state.json","well_known_bundle":"https://pith.science/.well-known/pith/PHRKRV6ESSHPUIF2L5Z5YZO6DO/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2020:PHRKRV6ESSHPUIF2L5Z5YZO6DO","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":"000d8b05a060c444136c40c6dca13b2073e5a164a7292050211ae5c9c1e9231a","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"physics.acc-ph","submitted_at":"2020-04-17T02:10:26Z","title_canon_sha256":"dbcb05dbc835aa152019a4a371a302cae80eda20a2aca06611ba5d7f85717139"},"schema_version":"1.0","source":{"id":"2004.08034","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2004.08034","created_at":"2026-07-05T01:23:06Z"},{"alias_kind":"arxiv_version","alias_value":"2004.08034v1","created_at":"2026-07-05T01:23:06Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2004.08034","created_at":"2026-07-05T01:23:06Z"},{"alias_kind":"pith_short_12","alias_value":"PHRKRV6ESSHP","created_at":"2026-07-05T01:23:06Z"},{"alias_kind":"pith_short_16","alias_value":"PHRKRV6ESSHPUIF2","created_at":"2026-07-05T01:23:06Z"},{"alias_kind":"pith_short_8","alias_value":"PHRKRV6E","created_at":"2026-07-05T01:23:06Z"}],"graph_snapshots":[{"event_id":"sha256:81de1c96cce9ef18ab1f1004972406d8c41d30d000f90ac78c68ad438db25951","target":"graph","created_at":"2026-07-05T01:23:06Z","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/2004.08034/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Reducing the intrinsic emittance of photocathodes is one of the most promising routes to improving the brightness of electron sources. However, when emittance growth occurs during beam transport (for example, due to space-charge), it is possible that this emittance growth overwhelms the contribution of the photocathode and, thus, in this case source emittance improvements are not beneficial. Using multi-objective genetic optimization, we investigate the role intrinsic emittance plays in determining the final emittance of several space-charge dominated photoinjectors, including those for high r","authors_text":"Bruce M. Dunham, Christopher M. Pierce, Colwyn Gulliford, Edmond Lu, Ivan V. Bazarov, Jared M. Maxson, Matthew B. Andorf, Matthew Gordon, Nora P. Norvell, Tor O. Raubenheimer, Young-Kee Kim","cross_cats":[],"headline":"","license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"physics.acc-ph","submitted_at":"2020-04-17T02:10:26Z","title":"The Role of Low Intrinsic Emittance in Modern Photoinjector Brightness"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2004.08034","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":"sha256:4c9dd6bb937eb21afc84145e1e781eaef319a2ce5b60f1ba2c45e466f6fe8dff","target":"record","created_at":"2026-07-05T01:23:06Z","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":"000d8b05a060c444136c40c6dca13b2073e5a164a7292050211ae5c9c1e9231a","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"physics.acc-ph","submitted_at":"2020-04-17T02:10:26Z","title_canon_sha256":"dbcb05dbc835aa152019a4a371a302cae80eda20a2aca06611ba5d7f85717139"},"schema_version":"1.0","source":{"id":"2004.08034","kind":"arxiv","version":1}},"canonical_sha256":"79e2a8d7c4948efa20ba5f73dc65de1b93f1bcfa13425daf5b69b72dadd893c7","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"79e2a8d7c4948efa20ba5f73dc65de1b93f1bcfa13425daf5b69b72dadd893c7","first_computed_at":"2026-07-05T01:23:06.029891Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T01:23:06.029891Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"MKbLRWzeJUNZA0TSfsAfI3tLpwZ2pOGH7CR6NwKb9v8TDgW45bZMNBU4yHVmL+X4pxWHVCOpwiV0ZpkCbOFRDQ==","signature_status":"signed_v1","signed_at":"2026-07-05T01:23:06.030409Z","signed_message":"canonical_sha256_bytes"},"source_id":"2004.08034","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:4c9dd6bb937eb21afc84145e1e781eaef319a2ce5b60f1ba2c45e466f6fe8dff","sha256:81de1c96cce9ef18ab1f1004972406d8c41d30d000f90ac78c68ad438db25951"],"state_sha256":"3327bc2e983c53104d045d9e93e3bbf4f2da9e3e7851dde1a6fe968f2bab360b"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"vjpwpu4kRQgDnyeXmf2wyqgQlb7YdII91WDOEiufDXDctYWZKXNbA1QnbGqOKmKvnI6MeuYdHh5jrAZ9hOzGAA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-18T21:51:58.954998Z","bundle_sha256":"464ea23f023c4028cc5fc8ef34dc397f8e7f9af75f553b133f93409c49cf780e"}}