Modified general cavity theory applied to the calculation of gamma dose in ⁶⁰Co thermoluminescence dosimetry

Burlin's general cavity theory for intermediate sized cavities incorporated two weighting factors: d, the average reduction in the electron fluence from the medium inside the cavity, and 1-d, the average fractional build-up to equilibrium of the cavity-generated electron spectrum-both calculated for an average path length g of electrons crossing the cavity. A new weighting factor d' has been introduced expressing the fact that average path length for medium- and cavity-generated electrons are not equal and this leads to a modified general cavity expression. The new expression is applied to ⁶⁰Co thermoluminescence dosimetry experimental results of other workers. For LiF TLD in all the media agreement with experiment is improved. There is a significant dependence of the theoretical results on the effective mass attenuation coefficient, indicating the need for further studies.