Should the ISO slab phantom be used for calibrations in terms of the new ICRU 95 operational quantity personal dose?

The applicability of the ISO slab phantom as calibration phantom for the new ICRU report 95 quantity personal dose should be legitimated by simulations and measurements of backscatter factors on the ISO slab phantom and, comparatively, on a human-like Alderson Rando phantom. An ionization chamber was used to determine backscatter factors for standardized X-ray spectra in the energy range of 16-250 keV and for gamma radiation of 137Cs (662 keV) and 60Co (1250 keV). For the validation of measurement results on the ISO slab, the results were compared with those obtained by means of Monte Carlo simulations using MCNP 6.

Catalogue of dose rate constants for more than 400 radionuclides in terms of ambient dose H and comparison of figures to ambient dose equivalent H(10).

In 2020, the International Commission on Radiation Units & Measurements ICRU has released Report 95 on "Operational Quantities for External Radiation Exposure". This publication introduced a new measurand, namely ambient dose H, as the operational quantity for external exposure to be applied in the future replacing ambient dose equivalent H(10). It should be noted that this change will make it necessary to adjust previously used constants and coefficients or at least to review them with regard to the new measurand.

Examination of applicability of the ISO slab phantom as calibration phantom for the new ICRU 95 operational quantity personal dose.

In this article, the proposal of the International Commission on Radiation Units and Measurements/International Commission on Radiological Protection (ICRU/ICRP), that the ISO slab phantom should continue to be used as a calibration phantom for the new ICRU Report 95 operational quantity personal dose should be legitimised by simulation and performance of experiments to determine backscatter factors on the ISO slab phantom and, in comparison, on an anthropomorphic Alderson Rando phantom. The scope of this work was restricted to the photon energy range of radiation qualities commonly used in x-ray diagnostics. For this purpose, a shadow-free diagnostic (SFD) ionisation chamber was used to measure backscatter factors for X radiation in the energy range of 24 keV to 118 keV.

A novel approach towards the calculation of dose rate constants for ambient dose equivalent H(10) by including low energy x-rays.

The nuclide-specific dose rate constant, formerly called gamma ray constant, is one of the most important quantities in practical radiation protection dosimetry. For radiation sources with known radionuclide composition and activity, the expected dose rates at various distances can easily be calculated with reasonable approximations. In addition, they serve as a planning basis for the design of shielding of radiation application rooms and facilities.

CONVERSION COEFFICIENTS FROM AIR KERMA TO DIRECTIONAL DOSE EQUIVALENT H'(0.07) FOR PHOTONS.

New conversion coefficients from air kerma free-in-air, Ka, to directional dose equivalent at 0.07mm depth, H'(0.07), are provided for monoenergetic values and for the spectra of the radiation qualities defined in ISO 4037-1.