3D track reconstruction of neutron-induced recoil protons in fluorescent nuclear track detectors (FNTDs)

Abstract

This work presents the analysis of the images acquired by 3D scans of Fluorescence Nuclear Track Detector (FNTD)-based neutron dosimeters irradiated with fast neutrons. The objective is to demonstrate the feasibility of 3D track-spot detection and trajectories reconstruction of recoil protons, offering a robust δ-ray filtering, and investigate if this analysis provides useful information on the exposure conditions, compared to the currently implemented single-layer analysis. The FNTD crystal volume was scanned with a confocal laser scanning microscope to obtain stacked images. The images were processed to detect the foreground track-spots, which were linked using a particle tracking software. We performed a statistical analysis of the recoil-protons reconstructed trajectories. The analyzed data show that it is possible to distinguish neutron spectra having different energies by analyzing the ranges of the detected particles. Moreover, we demonstrate that the incidence of radiation angle can be determined in directional fields. For a reliable detector evaluation, however, better statistics obtained by scanning larger area of the FNTD crystal is needed.