{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2009:3UBSEX3HZD774746PALR5UEGTF","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":"ba7a56af5cfe26202553145d1961fb5b47be12688959d4662a107bc1336b069e","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.ins-det","submitted_at":"2009-10-08T14:56:28Z","title_canon_sha256":"d5b22f10a48ed049ebee048a5c56d26893836bb7bc7f6342bfd539c4cc522dc1"},"schema_version":"1.0","source":{"id":"0910.1522","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"0910.1522","created_at":"2026-05-18T02:34:19Z"},{"alias_kind":"arxiv_version","alias_value":"0910.1522v2","created_at":"2026-05-18T02:34:19Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0910.1522","created_at":"2026-05-18T02:34:19Z"},{"alias_kind":"pith_short_12","alias_value":"3UBSEX3HZD77","created_at":"2026-05-18T12:25:58Z"},{"alias_kind":"pith_short_16","alias_value":"3UBSEX3HZD774746","created_at":"2026-05-18T12:25:58Z"},{"alias_kind":"pith_short_8","alias_value":"3UBSEX3H","created_at":"2026-05-18T12:25:58Z"}],"graph_snapshots":[{"event_id":"sha256:333996e9dc7121436b8f40ccf9aa1e25a2f297ce853aedc7f1c7a96845d8feba","target":"graph","created_at":"2026-05-18T02:34:19Z","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":"A two-stage Stirling-type U-shape pulse tube cryocooler driven by a 10 kW-class linear compressor was designed, built and tested. A special feature of the cold head is the absence of a heat exchanger at the cold end of the first stage, since the intended application requires no cooling power at this intermediate temperature. Simulations where done using Sage-software to find optimum operating conditions and cold head geometry. Flow-impedance matching was required to connect the compressor designed for 60 Hz operation to the 40 Hz cold head. A cooling power of 12.9 W at 25 K with an electrical ","authors_text":"G. Thummes, M. Dietrich","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.ins-det","submitted_at":"2009-10-08T14:56:28Z","title":"Two-stage high frequency pulse tube cooler for refrigeration at 25 K"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0910.1522","kind":"arxiv","version":2},"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:d8a9ca6b844c23f9daa83f0f6c897d3783402b416dd8bd2b1cb767511e3eef04","target":"record","created_at":"2026-05-18T02:34:19Z","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":"ba7a56af5cfe26202553145d1961fb5b47be12688959d4662a107bc1336b069e","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.ins-det","submitted_at":"2009-10-08T14:56:28Z","title_canon_sha256":"d5b22f10a48ed049ebee048a5c56d26893836bb7bc7f6342bfd539c4cc522dc1"},"schema_version":"1.0","source":{"id":"0910.1522","kind":"arxiv","version":2}},"canonical_sha256":"dd03225f67c8fffe7f9e78171ed0869973370ff002520dcc7e8ed4f146d1e6c8","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"dd03225f67c8fffe7f9e78171ed0869973370ff002520dcc7e8ed4f146d1e6c8","first_computed_at":"2026-05-18T02:34:19.647692Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:34:19.647692Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"O5iQ96KgTMauJ3jGb/8Gcx2lDZFs/+SZKbpNGVZcBvPIy5MggwGTfkjmYzB4A5AH8dGABXovYAGqdc0ZPcPIAg==","signature_status":"signed_v1","signed_at":"2026-05-18T02:34:19.648132Z","signed_message":"canonical_sha256_bytes"},"source_id":"0910.1522","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:d8a9ca6b844c23f9daa83f0f6c897d3783402b416dd8bd2b1cb767511e3eef04","sha256:333996e9dc7121436b8f40ccf9aa1e25a2f297ce853aedc7f1c7a96845d8feba"],"state_sha256":"72290a2e5232d50f50a11d47c9e57dae88f01036d6b8d75bf187316779e6e239"}