Determination of dose components in phantoms irradiated with an epithermal neutron beam for boron neutron capture therapy.

The application of activation foils, thermoluminescent detectors, and ionization chambers has been investigated for the determination of the different dose components in phantoms irradiated with a mixed gamma-ray and epithermal neutron beam for boron neutron capture therapy. The thermal neutron fluence has been determined using a set of AuAl and MnNi activation foils. TLD-700 and a Mg(Ar) ionization chamber have been used for the determination of the gamma-ray dose. The dose from epithermal neutrons has been determined using a TE(TE) ionization chamber. The detector characteristics and the relative sensitivities of the various detectors to the different dose components in the phantom have been determined. The following accuracies (1 standard deviation) in the determination of the different components have been obtained: thermal neutron fluence rate: 5%; gamma-ray dose rate: 7%; epithermal neutron dose rate: 15%. These values make these detectors suitable for obtaining the complete set of clinical dosimetry data required for patient dose assessment.