DOSE DEPENDENCE OF RADIATION INDUCED DAMAGE IN THE THERMOLUMINESCENT RESPONSE OF LIF:Mg,Ti (TLD-100)

Abstract

The effect of previous irradiation on the sensitivity of the glow peaks of LiF:Mg,Ti (TLD-100) is investigated up to levels of dose of 400 Gy in both slow-cooled and naturally cooled materials following the 400°C/1 hour pre-irradiation anneal. It is demonstrated that the naturally cooled samples can be re-used up to accumulated levels of dose of 50 Gy without recalibration. At 400 Gy a significant decrease in sensitivity of approximately 25% is observed for all the glow peaks (excluding peak 3). In slow-cooled materials even 100 Gy does not alter the sensitivity of the material.

Technical note: High‐dose and ultra‐high dose rate (UHDR) evaluation of Al2O3:C optically stimulated luminescent dosimeter nanoDots and powdered LiF:Mg,Ti thermoluminescent dosimeters for radiation therapy applications

“…Nevertheless, these dosimeters have the potential for use beyond this recommended 10-Gy limit. [24][25][26][27][28][29][30][31] A recent publication from Liu et al demonstrated the feasible use of Gafchromic EBT3 film at extended doses up to at least 50 Gy when utilizing only the red channel for dose measurements, without increasing the uncertainty in dose determination. 31 The aim of this study is to determine the usability of Al 2 O 3 :C OSLDs and single-use powder-based LiF:Mg,Ti TLDs with Gafchromic EBT3 film under high-dose, ultra-high DPP, and ultra-high dose rate conditions that extend beyond their recommended use in their respective Task Group reports 14,20 for applications in calibration and dose verification for FLASH RT.…”

“…Furthermore, FLASH RT has been proposed for use in single‐fraction or hypo‐fractionated regimens with a dose per fraction typically exceeding 10 Gy, which is outside the recommended dose range for Gafchromic film (in red channel dosimetry), TLDs, and OSLDs per AAPM's TG‐235 14 and TG‐191 20 reports. Nevertheless, these dosimeters have the potential for use beyond this recommended 10‐Gy limit 24–31 . A recent publication from Liu et al.…”