LET spectrometry for p+nat(Li+C) system at different proton energies using CR-39: Development of autoLET code for automated generation of LET spectra and dose values

Abstract

The present work describes measurement of LET (linear energy transfer) spectra due to neutrons generated from the p+nat(Li+C) system at 4 different proton energies (8, 12, 16 and 20 MeV) using CR-39 detector. A computer program (autoLET) was developed to process the track and the etching parameters for automated generation of the LET spectra and the corresponding dosimetric quantities. After chemical etching of irradiated CR-39 detectors, the track parameters were fed as inputs to the autoLET code to generate the LET spectra as well as to determine the track density and dosimetric quantities. FLUKA Monte Carlo simulations were performed to estimate the neutron fluence, energy spectrum and ambient dose equivalent for the same p+nat(Li+C) system. The measured track density and the dose equivalent were found to decrease initially from 8 to 12 MeV and further increased with increase in proton energy. Similar estimations for neutron fluence and ambient dose equivalent were also observed from the FLUKA simulations. The relative response of CR-39 in terms of track and dose equivalent determined for this radiation environment was found to be 1.60 × 10−4±3.85×10−5 track/n and 0.394 ± 0.054 respectively. The dose equivalent response (HLET/H*(10)) obtained in this study was compared with the data available in literature. The present study would be useful in estimating the neutron field around particle accelerator environment and for the radiation protection purposes in neutron generating facilities.