{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"754e68403429a196568d9d02e73077ab2912ea22d14f9c8a843cd86edebdf081","created":"2026-10-03T07:18:06Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"9db71ded85d009b395f528f5004afd97279856378df58ad224288be732f28c22","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"med.dosimetry.small-field-factors","kind":"well-posed","literature_status":"partially-resolved","n":"1","parents":[],"plain":"In beams only a few millimetres wide the detector itself disturbs the radiation it is measuring. The corrections needed are large and not known precisely.","posed_since":"2000","precise":"Determine field-output correction factors for active and passive detectors in photon fields of equivalent square side 2 to 20 mm, where lateral charged-particle equilibrium fails and source occlusion sets in, to a standard uncertainty below 1 percent. Required: detector-specific perturbation factors from Monte Carlo with validated geometry and from independent measurement. An answer is a correction-factor set with that uncertainty.","problem_ref":null,"references":"","settled_by":"Agreement within 1 percent between independent Monte Carlo and primary-standard measurements, such as water calorimetry, in the same small fields.","status_note":"The IAEA and AAPM TRS-483 formalism of 2017 supplies factors, with residual uncertainty above 1 percent for the smallest fields and some detectors.","title":"Detector correction factors in millimetre-scale fields","topic_ref":"be2989252171f9f987d92f4b562e96075370f97879f879218827602913f7731c"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"0cb2270d49b9468dc3e08962fae94ca028f4e20c17384a8208057ea0ccb1c8f9","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"5ef01bdabe4e018d8b4903ced74dfdef052008863dce9670b6f7faa02b50291b","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"Jq_uWMOrTOuz6gXVLGrrV-MTR4mPm-snqQSNG966OuhuHETJ-78hbvJY2oVonEoCpcam1R0o4_rMbVJxzWilDg"},"schema":"pubphys.envelope/1"},"record_hash":"0cb2270d49b9468dc3e08962fae94ca028f4e20c17384a8208057ea0ccb1c8f9","leaf_index":1675}