Estimation of gamma dose in neutron dosimetry using peak 4 to 5 ratios in Lif:Mg,Ti (TLD-100/600)

This work investigates the possibility of extracting ancillary information from the TLD-100/600 glow curve, specifically, peak 4 to peak 5 ratios, as an aid to increasing the accuracy/reliability of the estimation of gamma dose in neutron dosimetry. Following irradiation in a pure gamma ray radiation field (⁶⁰Co) the intensity of peak 4 relative to that of peak 5 is 0.35 ± 0.05 (1 SD), whereas, irradiation by Am-Be neutrons results in a ratio of 0.13 ± 0.02 (1 SD) (air annealing). The accuracy of the evaluation of the neutron/gamma dose components (D(n), D(g)) was investigated by separately irradiating polyethylene encapsulated TLD-600 chips by ⁶⁰Co gamma rays (D(g)) and Am-Be neutrons (D(n)) to known levels of dose between various values of D(g)/D(n + g) from 0.02 to 0.10. For these dose ratios, the accuracy of separation is excellent. Accurate separation of the dose components at higher values of D(g) relative to D(n) (> 0.1) requires further development of the deconvolution technique to improve the reproducibility of the deconvolution of peaks 4 and 5.