dosimetry

EPR-based technique was optimized for accident dosimetry using human and mice teeth. It successfully reconstructed radiation doses to tooth enamel from 100 mGy to 700 mGy. The JEOL Jes-FA EPR spectrometer was optimized to control noise and used multiple measurements for maximum sensitivity. We improved measurement reproducibility through Q value normalization and digital Mn++ marker alignment. The undesirable signals were limited by reducing mechanical treatment and using liquid nitrogen cooling. The dosimetric signal anisotropy was reduced by manually rotating the sample in the cavity. Uniform known doses were delivered using a customized 3D irradiation rack, and post-processing involved fitting functions for both native and dosimetric signals, with selective power saturation for quick dose reconstruction at higher doses.

This study investigated the neutron response of human tooth enamel using an accelerator-based neutron source in the mean energy range 150 to 450 keV. The neutron beam was generated with a low gamma radiation yield 7Li(p, n)7Be type thick target bombarded with 3MeV proton beam, and dosimetry was performed using a pre-calibrated neutron dosimeter. The neutron irradiation induces a dosimetric signal in tooth enamel similar to that produced by gamma rays, with the signal growing linearly with neutron dose. Larger enamel grains exhibited a higher dosimetric amplitude. The study found that the neutron response of tooth enamel is 8-12% of the gamma ray response, suggesting a correction factor of 10 for neutron dosimetry in tooth enamel