Dose distributions in phantoms irradiated in thermal columns of two different nuclear reactors.

In-phantom dosimetry studies have been carried out at the thermal columns of a thermal- and a fast-nuclear reactor for investigating: (a) the spatial distribution of the gamma dose and the thermal neutron fluence and (b) the accuracy at which the boron concentration should be estimated in an explanted organ of a boron neutron capture therapy patient. The phantom was a cylinder (11 cm in diameter and 12 cm in height) of tissue-equivalent gel. Dose images were acquired with gel dosemeters across the axial section of the phantom.