A new double dose measurement method for TLD-100H.

Sallah A., D'Anna A., Galvagno R., Gueli A.M., Matamoros A., Stella G.
  Giovedì 15/09   09:00 - 13:00   Aula Bonetti   V - Biofisica e fisica medica   Presentazione
The aim of this work was to investigate optically and thermally stimulated luminescence (OSL and TL) properties of lithium fluoride (LiF) doped with magnesium (Mg), copper (Cu) and phosphorous (P) (LiF:Mg, Cu, P), commercially known as TLD-100H. Greater accuracy and precision of dosimetric measurements can be achieved through a method that allows, for each irradiation, two independent dose measurements. Pre-and post-annealing conditions, their effects on the OSL and TL curves, the ideal temperature during OSL readout, and fading properties were investigated. Optimal parameters were obtained and used for calibration curves determination. For irradiation and readout was employed a Ris\o$ TL/OSL DA 15 system equipped with a calibrated $^{90}Sr/^{90}Y$ beta source, blue LEDs ({470 $nm \pm$ 30 ${nm}$) for optically stimulation, a thermocouple for thermal stimulation, and a bialkali EMI 9235QB PMT for light detection. Calibration curves showed two different trends for TL and OSL values $vs.$ absorbed dose in the range from 0 and $4 {Gy}$, $i.e.$, a polynomial trend for TL and linear one for OSL. This result confirms the independent response for the two stimulation methods.