{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2018:QY52EGDBXWIA5J324QFLICUULF","short_pith_number":"pith:QY52EGDB","canonical_record":{"source":{"id":"1804.07487","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.acc-ph","submitted_at":"2018-04-20T08:35:26Z","cross_cats_sorted":["physics.app-ph"],"title_canon_sha256":"1ed92a04c1d20a7a5cfd8dd54a62ad52fe3a651ebab86870eb8307ae28dd3f33","abstract_canon_sha256":"8f1d0ec61b30c4f21e2b7d98f325f9c1a4536805c116f78a51f71146a6b8266a"},"schema_version":"1.0"},"canonical_sha256":"863ba21861bd900ea77ae40ab40a9459680dcdb924864e030de922e802c389da","source":{"kind":"arxiv","id":"1804.07487","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1804.07487","created_at":"2026-05-18T00:17:58Z"},{"alias_kind":"arxiv_version","alias_value":"1804.07487v1","created_at":"2026-05-18T00:17:58Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1804.07487","created_at":"2026-05-18T00:17:58Z"},{"alias_kind":"pith_short_12","alias_value":"QY52EGDBXWIA","created_at":"2026-05-18T12:32:50Z"},{"alias_kind":"pith_short_16","alias_value":"QY52EGDBXWIA5J32","created_at":"2026-05-18T12:32:50Z"},{"alias_kind":"pith_short_8","alias_value":"QY52EGDB","created_at":"2026-05-18T12:32:50Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2018:QY52EGDBXWIA5J324QFLICUULF","target":"record","payload":{"canonical_record":{"source":{"id":"1804.07487","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.acc-ph","submitted_at":"2018-04-20T08:35:26Z","cross_cats_sorted":["physics.app-ph"],"title_canon_sha256":"1ed92a04c1d20a7a5cfd8dd54a62ad52fe3a651ebab86870eb8307ae28dd3f33","abstract_canon_sha256":"8f1d0ec61b30c4f21e2b7d98f325f9c1a4536805c116f78a51f71146a6b8266a"},"schema_version":"1.0"},"canonical_sha256":"863ba21861bd900ea77ae40ab40a9459680dcdb924864e030de922e802c389da","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T00:17:58.675089Z","signature_b64":"m77VCFPO9jFcNTTno72Xngd01VS5+7d+Z7iXMWsiCZcUvrgAfJdghjS6jrsCy61B7FKvAczcVx5Vw4Zy98hIAw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"863ba21861bd900ea77ae40ab40a9459680dcdb924864e030de922e802c389da","last_reissued_at":"2026-05-18T00:17:58.674402Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T00:17:58.674402Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1804.07487","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":"2026-05-18T00:17:58Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"951BhYDec16L5wcM0bOOvR6Uax45BNWC9vNVJ64LTaoSMfQCQIfvu+jT4Z3XdVsAmsKGs6MqHuGUuDAwgN2iDw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-31T04:48:21.758955Z"},"content_sha256":"db6f3fe1e6f36d8f52e98c158f0c8b0b12ca0e42cd1e6f7505ec1d563e34fff7","schema_version":"1.0","event_id":"sha256:db6f3fe1e6f36d8f52e98c158f0c8b0b12ca0e42cd1e6f7505ec1d563e34fff7"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2018:QY52EGDBXWIA5J324QFLICUULF","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"XPS studies of nitrogen doping niobium used for accelerator applications","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["physics.app-ph"],"primary_cat":"physics.acc-ph","authors_text":"Deyu Yang, Jifei Zhao, Kui Zhou, Weiwei Tan, Xiangyang Lu, Yuan He, Yujia Yang, Ziqin Yang","submitted_at":"2018-04-20T08:35:26Z","abstract_excerpt":"Nitrogen doping study on niobium (Nb) samples used for the fabrication of superconducting radio frequency (SRF) cavities was carried out. The samples' surface treatment was attempted to replicate that of the Nb SRF cavities, which includes heavy electropolishing (EP), nitrogen doping and the subsequent EP with different amounts of material removal. The surface chemical composition of Nb samples with different post treatments has been studied by XPS. The chemical composition of Nb, O, C and N was presented before and after Gas Cluster Ion Beam (GCIB) etching. No signals of poorly superconductin"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1804.07487","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":""},"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":"2026-05-18T00:17:58Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"ksNHNrtEoD7KN8+obnxpDPolpLIEXJaIR0aYtWaihI6bPLbGtoTks/LIzieJ4K6cWvfBJgW6+WaRKSQCcqZvBw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-31T04:48:21.759298Z"},"content_sha256":"81fe3d8ab8fb8afa936fe89e2867085a5511402d15b57323cea886b674a49f28","schema_version":"1.0","event_id":"sha256:81fe3d8ab8fb8afa936fe89e2867085a5511402d15b57323cea886b674a49f28"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/QY52EGDBXWIA5J324QFLICUULF/bundle.json","state_url":"https://pith.science/pith/QY52EGDBXWIA5J324QFLICUULF/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/QY52EGDBXWIA5J324QFLICUULF/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":"2026-05-31T04:48:21Z","links":{"resolver":"https://pith.science/pith/QY52EGDBXWIA5J324QFLICUULF","bundle":"https://pith.science/pith/QY52EGDBXWIA5J324QFLICUULF/bundle.json","state":"https://pith.science/pith/QY52EGDBXWIA5J324QFLICUULF/state.json","well_known_bundle":"https://pith.science/.well-known/pith/QY52EGDBXWIA5J324QFLICUULF/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2018:QY52EGDBXWIA5J324QFLICUULF","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":"8f1d0ec61b30c4f21e2b7d98f325f9c1a4536805c116f78a51f71146a6b8266a","cross_cats_sorted":["physics.app-ph"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.acc-ph","submitted_at":"2018-04-20T08:35:26Z","title_canon_sha256":"1ed92a04c1d20a7a5cfd8dd54a62ad52fe3a651ebab86870eb8307ae28dd3f33"},"schema_version":"1.0","source":{"id":"1804.07487","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1804.07487","created_at":"2026-05-18T00:17:58Z"},{"alias_kind":"arxiv_version","alias_value":"1804.07487v1","created_at":"2026-05-18T00:17:58Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1804.07487","created_at":"2026-05-18T00:17:58Z"},{"alias_kind":"pith_short_12","alias_value":"QY52EGDBXWIA","created_at":"2026-05-18T12:32:50Z"},{"alias_kind":"pith_short_16","alias_value":"QY52EGDBXWIA5J32","created_at":"2026-05-18T12:32:50Z"},{"alias_kind":"pith_short_8","alias_value":"QY52EGDB","created_at":"2026-05-18T12:32:50Z"}],"graph_snapshots":[{"event_id":"sha256:81fe3d8ab8fb8afa936fe89e2867085a5511402d15b57323cea886b674a49f28","target":"graph","created_at":"2026-05-18T00:17:58Z","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"},"paper":{"abstract_excerpt":"Nitrogen doping study on niobium (Nb) samples used for the fabrication of superconducting radio frequency (SRF) cavities was carried out. The samples' surface treatment was attempted to replicate that of the Nb SRF cavities, which includes heavy electropolishing (EP), nitrogen doping and the subsequent EP with different amounts of material removal. The surface chemical composition of Nb samples with different post treatments has been studied by XPS. The chemical composition of Nb, O, C and N was presented before and after Gas Cluster Ion Beam (GCIB) etching. No signals of poorly superconductin","authors_text":"Deyu Yang, Jifei Zhao, Kui Zhou, Weiwei Tan, Xiangyang Lu, Yuan He, Yujia Yang, Ziqin Yang","cross_cats":["physics.app-ph"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.acc-ph","submitted_at":"2018-04-20T08:35:26Z","title":"XPS studies of nitrogen doping niobium used for accelerator applications"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1804.07487","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:db6f3fe1e6f36d8f52e98c158f0c8b0b12ca0e42cd1e6f7505ec1d563e34fff7","target":"record","created_at":"2026-05-18T00:17:58Z","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":"8f1d0ec61b30c4f21e2b7d98f325f9c1a4536805c116f78a51f71146a6b8266a","cross_cats_sorted":["physics.app-ph"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.acc-ph","submitted_at":"2018-04-20T08:35:26Z","title_canon_sha256":"1ed92a04c1d20a7a5cfd8dd54a62ad52fe3a651ebab86870eb8307ae28dd3f33"},"schema_version":"1.0","source":{"id":"1804.07487","kind":"arxiv","version":1}},"canonical_sha256":"863ba21861bd900ea77ae40ab40a9459680dcdb924864e030de922e802c389da","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"863ba21861bd900ea77ae40ab40a9459680dcdb924864e030de922e802c389da","first_computed_at":"2026-05-18T00:17:58.674402Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:17:58.674402Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"m77VCFPO9jFcNTTno72Xngd01VS5+7d+Z7iXMWsiCZcUvrgAfJdghjS6jrsCy61B7FKvAczcVx5Vw4Zy98hIAw==","signature_status":"signed_v1","signed_at":"2026-05-18T00:17:58.675089Z","signed_message":"canonical_sha256_bytes"},"source_id":"1804.07487","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:db6f3fe1e6f36d8f52e98c158f0c8b0b12ca0e42cd1e6f7505ec1d563e34fff7","sha256:81fe3d8ab8fb8afa936fe89e2867085a5511402d15b57323cea886b674a49f28"],"state_sha256":"27e81ac4dd397c18b6c56d6d175e20a4c233a6db18e0f1fb73394c9776a6d997"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"ijglXW7b3EZxZLDTQa2gdDhV+UTWOCXIOUF2NzaPsMDpMS9EOg+FUSKYyQF18xTQ88sN0GpL2GkoKuG3N5mvDA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-31T04:48:21.761414Z","bundle_sha256":"c5872176ab8349825dc5f735eb2785a8bd3c38fc9fbb2e464ab60acc169762b1"}}