{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"a674ae4ed42d5881a57125d6d80d5458cb8f977340856b744ef44b4315db336f","created":"2026-10-03T07:18:06Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"cc4a172774cab5b0375e9b03b05b956328f4b6352504c97bf286e5c9931cbf96","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"med.dosimetry.uhdr-standards","kind":"well-posed","literature_status":"open","n":"1","parents":[],"plain":"Standard dose meters saturate when the dose arrives in a single very intense pulse, because the charges they collect recombine before being counted. There is no accepted way to measure such doses absolutely.","posed_since":"2018","precise":"Establish traceable absolute dosimetry for pulses delivering 100 to 1000 rad in 1 to 4 microseconds, with instantaneous dose rates up to $10^9\\,\\mathrm{rad}/\\mathrm{s}$, where ion-chamber general recombination is severe and the Boag formalism (the standard correction for charge recombination in ion chambers) fails. Candidate standards: water and graphite calorimetry, Fricke and alanine chemical dosimeters, scintillator and Cherenkov detectors. An answer is a primary standard plus validated transfer detectors with uncertainty below 2 percent.","problem_ref":null,"references":"","settled_by":"Agreement within 2 percent between calorimetric primary standards and transfer dosimeters across the pulse-structure range.","status_note":"Calorimeter-based ultra-high dose-rate standards were under development at several national laboratories as of 2025.","title":"Absolute dosimetry at ultra-high dose rate","topic_ref":"be2989252171f9f987d92f4b562e96075370f97879f879218827602913f7731c"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"e6e5e4aba010e4e14032d79bcc14cc419d7a3ccdd1b60f5d284fff87bf0127ad","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"45c5f775d002f7c45001a320f520e4a6e75868e2c1bc94b2c4d2ce2f2db44c20","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"IEgP8DBe3PUXEYFt9S8dZ3faxX6PZ8HKgWPaFk1KA42d2BRJ0zmEtbpyjGUp-nIdLIkW6KvSa1PkfqIiUKmqDA"},"schema":"pubphys.envelope/1"},"record_hash":"e6e5e4aba010e4e14032d79bcc14cc419d7a3ccdd1b60f5d284fff87bf0127ad","leaf_index":1677}