Comparison of Gamma-Ray Heating Measurements Using Thermoluminescent Dosimeters with Calculations

Gamma-ray heating rates from ⁶⁰Co and ¹³⁷Cs are measured independently in a stainless steel sphere using thermoluminescent dosimeters (TLDs) with different sensitivities and atomic numbers, a useful check on dosimetric measurements. Gamma-ray dose-weighting f factors, based on the general cavity ionization theory, are applied to convert the net TLD dose rates into gamma-ray heating rates in stainless steel. Gamma-ray spectra are calculated using the ANISN computer code together with the DLC-41/VITAMINC cross-section library. The experimental and the calculated gamma-ray heating rates are compared. The calculation-to-experiment (C/E) ratios of the heating rates are close to unity at experimental positions near the gamma-ray source and show drop-off at far positions. This C/E discrepancy comes primarily from the calculations; however, there is a minor contribution to the C/E discrepancy from the TLD overresponse at low gamma energies.