Sensitivity of whole human teeth to fast neutrons and gamma-rays estimated by L-band EPR spectroscopy.

This paper reports the first attempt to use L-band spectroscopy for estimating the sensitivity of whole teeth to fast neutrons and gamma-rays. Three teeth were successively irradiated first with fast neutrons with a wide energy spectrum (mean energy around 30 MeV) up to approximately 160 Gy and then with gamma-rays up to approximately 14 Gy. After each irradiation, L-band (approximately 1 GHz) EPR spectra of each whole tooth surrounded by the surface-coil resonator were recorded, yielding a single composite line principally due to CO2- and native radicals. The sensitivities are estimated by the slopes of the linear dose response curves of the dosimetric CO2- radicals. The ratios of the gamma/neutron sensitivities were found to be in the range 8-9 (+/- 2) for the three teeth. c2002 Elsevier Science Ltd. All rights reserved.