title: The use of neutron and gamma ray spectral measurements and calculations to obtain dosimetric information for DT neutrons.
abstract: Neutron and gamma ray energy spectra were measured using an NE-213 scintillator at depths of 7.2, 15.2, and 22.2 cm in a tissue-equivalent phantom which was uniformly irradiated on one face by deuterium-tritium (DT) neutrons. Coupled neutron-gamma ray multigroup discrete ordinates calculations were performed using semi-infinite slab geometry. These calculations were used to supplement the measured spectra below 1 MeV. Similar calculations were performed to study the perturbation in the phantom due to the detector. The measured and calculated spectra were used to determine the kerma distributions for neutrons and gamma rays at each location. The gamma radiation was determined to contribute more than 10% of the total dose at each depth. The calculated kerma also reveals that a knowledge of the gamma ray spectra below 1 MeV is desirable.
mesh_terms: D005720:Gamma Rays; D008961:Models, Structural; D009502:Neutrons; D011879:Radiotherapy Dosage; D012588:Scintillation Counting / Q000295:instrumentation