Revision 1

Accepted · first revision · record

Title: Detector correction factors in millimetre-scale fields
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.
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.
Settled by: Agreement within 1 percent between independent Monte Carlo and primary-standard measurements, such as water calorimetry, in the same small fields.
Kind: well-posed
Answer type: value
References: (empty)
Literature status: partially-resolved
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.
Posed since: 2000