{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2019:XEPECD7N6BPXXFWN4IZZRUOUDW","short_pith_number":"pith:XEPECD7N","canonical_record":{"source":{"id":"1910.11926","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"physics.acc-ph","submitted_at":"2019-10-25T20:39:30Z","cross_cats_sorted":[],"title_canon_sha256":"6daddbf09b991fa5ebead15ae89883b5d4df3257b24fcbdb32278e2c529b7c37","abstract_canon_sha256":"e12be3416ce5e204a03ff045304937ec71f3e3bfc012bf2d63a35b4d9fd0bcea"},"schema_version":"1.0"},"canonical_sha256":"b91e410fedf05f7b96cde23398d1d41dba689f64c00220e26cbd0456be55fb42","source":{"kind":"arxiv","id":"1910.11926","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1910.11926","created_at":"2026-07-05T00:41:44Z"},{"alias_kind":"arxiv_version","alias_value":"1910.11926v1","created_at":"2026-07-05T00:41:44Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1910.11926","created_at":"2026-07-05T00:41:44Z"},{"alias_kind":"pith_short_12","alias_value":"XEPECD7N6BPX","created_at":"2026-07-05T00:41:44Z"},{"alias_kind":"pith_short_16","alias_value":"XEPECD7N6BPXXFWN","created_at":"2026-07-05T00:41:44Z"},{"alias_kind":"pith_short_8","alias_value":"XEPECD7N","created_at":"2026-07-05T00:41:44Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2019:XEPECD7N6BPXXFWN4IZZRUOUDW","target":"record","payload":{"canonical_record":{"source":{"id":"1910.11926","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"physics.acc-ph","submitted_at":"2019-10-25T20:39:30Z","cross_cats_sorted":[],"title_canon_sha256":"6daddbf09b991fa5ebead15ae89883b5d4df3257b24fcbdb32278e2c529b7c37","abstract_canon_sha256":"e12be3416ce5e204a03ff045304937ec71f3e3bfc012bf2d63a35b4d9fd0bcea"},"schema_version":"1.0"},"canonical_sha256":"b91e410fedf05f7b96cde23398d1d41dba689f64c00220e26cbd0456be55fb42","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T00:41:44.604249Z","signature_b64":"VrU+enFZgnFBYvjdH9grwBU9jmvhxl8PtRud9VCmRbaL8fU8P//JshZ18zytBdCcLRYD6EjdDTMOBNEZvLmzBw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"b91e410fedf05f7b96cde23398d1d41dba689f64c00220e26cbd0456be55fb42","last_reissued_at":"2026-07-05T00:41:44.603753Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T00:41:44.603753Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1910.11926","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":"2026-07-05T00:41:44Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"ef88ARiZhxmWWlwAwkLP/iNUpYYyk242pE9E6J2H45iszu9LGbxZt+aFQKE9flHt/kJjFFPUz2/44yVFsyG/Cw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-24T02:32:25.336339Z"},"content_sha256":"a36507a5f4df1bfaaf39ce84eae59eb12d6c3177281e25c73a35f0271ede6056","schema_version":"1.0","event_id":"sha256:a36507a5f4df1bfaaf39ce84eae59eb12d6c3177281e25c73a35f0271ede6056"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2019:XEPECD7N6BPXXFWN4IZZRUOUDW","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Mapping Photocathode Quantum Efficiency with Ghost Imaging","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":[],"primary_cat":"physics.acc-ph","authors_text":"D. Ratner, F. Cropp, K. Kabra, P. Musumeci, S. Li, T. J. Lane","submitted_at":"2019-10-25T20:39:30Z","abstract_excerpt":"Measuring the quantum efficiency (QE) map of a photocathode injector typically requires laser scanning, an invasive operation that involves modifying the injector laser focus and rastering the focused laser spot across the photocathode surface. Raster scanning interrupts normal operation and takes considerable time to setup. In this paper, we demonstrate a novel method of measuring the QE map using a ghost imaging framework that correlates the injector laser spatial variation over time with the total charge yield. Ghost imaging enables passive, real-time monitoring of the QE map without manual"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1910.11926","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/1910.11926/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":"2026-07-05T00:41:44Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"jqz+X4flxvUiGbbCi4tBlD4TWu57VBqW1k2dRUDNEvGSBA1oQxlaMEYN8iDrmbmZayg+NOIQuay9yqVWe9QyBQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-24T02:32:25.337137Z"},"content_sha256":"ba6d68b29deeb8ab299dae5ae1317de4cd2ca21cb520ffbd08ea803e50fbed29","schema_version":"1.0","event_id":"sha256:ba6d68b29deeb8ab299dae5ae1317de4cd2ca21cb520ffbd08ea803e50fbed29"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/XEPECD7N6BPXXFWN4IZZRUOUDW/bundle.json","state_url":"https://pith.science/pith/XEPECD7N6BPXXFWN4IZZRUOUDW/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/XEPECD7N6BPXXFWN4IZZRUOUDW/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":"2026-08-24T02:32:25Z","links":{"resolver":"https://pith.science/pith/XEPECD7N6BPXXFWN4IZZRUOUDW","bundle":"https://pith.science/pith/XEPECD7N6BPXXFWN4IZZRUOUDW/bundle.json","state":"https://pith.science/pith/XEPECD7N6BPXXFWN4IZZRUOUDW/state.json","well_known_bundle":"https://pith.science/.well-known/pith/XEPECD7N6BPXXFWN4IZZRUOUDW/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2019:XEPECD7N6BPXXFWN4IZZRUOUDW","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":"e12be3416ce5e204a03ff045304937ec71f3e3bfc012bf2d63a35b4d9fd0bcea","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"physics.acc-ph","submitted_at":"2019-10-25T20:39:30Z","title_canon_sha256":"6daddbf09b991fa5ebead15ae89883b5d4df3257b24fcbdb32278e2c529b7c37"},"schema_version":"1.0","source":{"id":"1910.11926","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1910.11926","created_at":"2026-07-05T00:41:44Z"},{"alias_kind":"arxiv_version","alias_value":"1910.11926v1","created_at":"2026-07-05T00:41:44Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1910.11926","created_at":"2026-07-05T00:41:44Z"},{"alias_kind":"pith_short_12","alias_value":"XEPECD7N6BPX","created_at":"2026-07-05T00:41:44Z"},{"alias_kind":"pith_short_16","alias_value":"XEPECD7N6BPXXFWN","created_at":"2026-07-05T00:41:44Z"},{"alias_kind":"pith_short_8","alias_value":"XEPECD7N","created_at":"2026-07-05T00:41:44Z"}],"graph_snapshots":[{"event_id":"sha256:ba6d68b29deeb8ab299dae5ae1317de4cd2ca21cb520ffbd08ea803e50fbed29","target":"graph","created_at":"2026-07-05T00:41:44Z","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/1910.11926/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Measuring the quantum efficiency (QE) map of a photocathode injector typically requires laser scanning, an invasive operation that involves modifying the injector laser focus and rastering the focused laser spot across the photocathode surface. Raster scanning interrupts normal operation and takes considerable time to setup. In this paper, we demonstrate a novel method of measuring the QE map using a ghost imaging framework that correlates the injector laser spatial variation over time with the total charge yield. Ghost imaging enables passive, real-time monitoring of the QE map without manual","authors_text":"D. Ratner, F. Cropp, K. Kabra, P. Musumeci, S. Li, T. J. Lane","cross_cats":[],"headline":"","license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"physics.acc-ph","submitted_at":"2019-10-25T20:39:30Z","title":"Mapping Photocathode Quantum Efficiency with Ghost Imaging"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1910.11926","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:a36507a5f4df1bfaaf39ce84eae59eb12d6c3177281e25c73a35f0271ede6056","target":"record","created_at":"2026-07-05T00:41:44Z","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":"e12be3416ce5e204a03ff045304937ec71f3e3bfc012bf2d63a35b4d9fd0bcea","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"physics.acc-ph","submitted_at":"2019-10-25T20:39:30Z","title_canon_sha256":"6daddbf09b991fa5ebead15ae89883b5d4df3257b24fcbdb32278e2c529b7c37"},"schema_version":"1.0","source":{"id":"1910.11926","kind":"arxiv","version":1}},"canonical_sha256":"b91e410fedf05f7b96cde23398d1d41dba689f64c00220e26cbd0456be55fb42","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"b91e410fedf05f7b96cde23398d1d41dba689f64c00220e26cbd0456be55fb42","first_computed_at":"2026-07-05T00:41:44.603753Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T00:41:44.603753Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"VrU+enFZgnFBYvjdH9grwBU9jmvhxl8PtRud9VCmRbaL8fU8P//JshZ18zytBdCcLRYD6EjdDTMOBNEZvLmzBw==","signature_status":"signed_v1","signed_at":"2026-07-05T00:41:44.604249Z","signed_message":"canonical_sha256_bytes"},"source_id":"1910.11926","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:a36507a5f4df1bfaaf39ce84eae59eb12d6c3177281e25c73a35f0271ede6056","sha256:ba6d68b29deeb8ab299dae5ae1317de4cd2ca21cb520ffbd08ea803e50fbed29"],"state_sha256":"4a45f911a2b705d5e9e1b4fea3e01a879f4fc9259538bb891c4f0f2174cef952"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"FMTmpQR9rIXwcG85V+HPlADhyweRJd7xZ1N+bZllCy0fpzu69xJ8l+cmdgxXToykvTWRPWZ7AdZEjfBoL8dMDA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-24T02:32:25.343775Z","bundle_sha256":"96468c91454537f1db23563589a0e5c5c73acc0d64d21bcb2e3a51b6917f9f56"}}