Thermoluminescence solid-state nanodosimetry- the peak 5A/5 dosemeter

Authors

Anatoly B. Rosenfeld, University of WollongongFollow
L Oster
A Horowitz, Crystal Growth Division, Beersheva Israel
E Fuks, Ben Gurion University, Beersheva Israel
S Marino, Columbia University New York USA
H Datz, Radiation Safety Division, Yavne Israel
Y S. Horowitz, Crystal Growth Division, NRC-N, Beersheva Israel
M Rainer, ANSTO

RIS ID

36174

Publication Details

Fuks, E., Horowitz, Y. S., Oster, L., Marino, S., Rainer, M., Rozenfeld, A., Horowitz, A. and Datz, H. (2011). Thermoluminescence solid-state nanodosimetry- the peak 5A/5 dosemeter. Radiation Protection Dosimetry, 143 (2-4), 416-426.

Abstract

The shape of composite peak 5 in the glow curve of LiF:Mg,Ti (TLD-100) following ⁹⁰Sr/⁹⁰Y beta irradiation, previously demonstrated to be dependent on the cooling rate used in the 400°C pre-irradiation anneal, is shown to be dependent on ionisation density in both naturally cooled and slow-cooled samples. Following heavy-charged particle high-ionisation density (HID) irradiation, the temperature of composite peak 5 decreases by ∼5°C and the peak becomes broader. This behaviour is attributed to an increase in the relative intensity of peak 5a (a low-temperature satellite of peak 5). The relative intensity of peak 5a is estimated using a computerised glow curve deconvolution code based on first-order kinetics. The analysis uses kinetic parameters for peaks 4 and 5 determined from ancillary measurements resulting in nearly ‘single-glow peak’ curves for both the peaks. In the slow-cooled samples, owing to the increased relative intensity of peak 5a compared with the naturally cooled samples, the precision of the measurement of the 5a/5 intensity ratio is found to be ∼15 % (1 SD) compared with ∼25 % for the naturally cooled samples. The ratio of peak 5a/5 in the slow-cooled samples is found to increase systematically and gradually through a variety of radiation fields from a minimum value of 0.13±0.02 for ⁹⁰Sr/⁹⁰Y low-ionisation density irradiations to a maximum value of ∼0.8 for 20 MeV Cu and I ion HID irradiations. Irradiation by low-energy electrons of energy 0.1–1.5 keV results in values between 1.27 and 0.95, respectively. The increasing values of the ratio of peak 5a/5 with increasing ionisation density demonstrate the viability of the concept of the peak 5a/5 nanodosemeter and its potential in the measurement of average ionisation density in a ‘nanoscopic’ mass containing the trapping centre/luminescent centre spatially correlated molecule giving rise to composite peak 5.