Dosimetry of d(14)+Be neutrons with the two-peak method of LiF TLD-700

Abstract

The utility of LiF TLD-700 for the dosimetry of neutron beams are assessed. The fact that for in-phantom irradiations the 200 degrees C peak of TLD-700 has a much lower sensitivity to neutrons than to gamma rays and the higher temperature peak has comparable sensitivities to both radiations is of relevance from the point of view of the use of the two-peak method for the dosimetry of therapeutically used fast-neutron beams. The difference in the neutron sensitivities of the two peaks of TLD-700 is greater than that of the peaks of any other TLD including CaF:Tm. Since the gamma ray absorbed dose content in cyclotron-produced neutron beams is small, the supralinearity of the high-temperature glow peak does not pose a serious problem. Also by using thin ribbons, slow heating rates (about 3.5 degrees C s-1) during the TL readout and by applying predetermined individual calibration factors for each peak of each detector, the intensities of the glow peaks could be measured with a reasonable precision.