Experimental Estimation of Conversion Factors Between Air Kerma Free-in-Air and Individual Dose Equivalent Penetrating for 4-7 MeV Photons

Abstract

The conversion factor for 4-7 MeV photons for conversion from the air Kerma free-in-air to the ambient dose equivalent is 1.11-1.10 according to ICRP publication 51. For normal incidence the ambient dose equivalent corresponds to the directional dose equivalent at 10 mm depth in the ICRU sphere. The directional dose equivalent at 10 mm depth is considered as a good approximation of the individual dose equivalent, penetrating. Measurements with TL dosemeters on and in a PMMA slab phantom are compared with air kerma for 4-7 MeV photons. The measurements show that the conversion factor for 4-7 MeV photons for conversion from the air kerma free-in-air to the dose equivalent at 8 mm in a PMMA slab plantom is in the range 1.12-1.08