High-dose high-temperature emission of LiF:Mg,Cu,P: thermally and radiation induced loss & recovery of its sensitivity

TL;DR

This study develops a thermal treatment process to fully restore the sensitivity of LiF:Mg,Cu,P detectors after high-dose, high-temperature radiation measurements, enabling their reuse for accurate dose assessment across a wide range.

Contribution

It introduces a specific annealing procedure that fully recovers the sensitivity of MCP detectors post high-dose, high-temperature irradiation, allowing for their reuse.

Findings

Full sensitivity recovery achieved after annealing at 400-700°C

Detectors can be reused multiple times after high-dose measurements

Thermal treatment restores detector performance for wide dose ranges

Abstract

Highly sensitive LiF:Mg,Cu,P (MCP) detectors enable measurements of radiation doses from tens of nanograys up to a few kilograys, where the saturation of the signal of the main dosimetric peak occurs. Thanks to the recently observed high-dose high-temperature emission of MCP detectors heated to temperatures up to 600{\deg}C after exposures to radiation doses ranging from 1 kGy to 1 MGy, a new method of TL measurement of radiation doses has been recently developed at the Institute of Nuclear Physics (IFJ). This method can measure doses ranging from micrograys up to a megagray. So far, high dose measurements were performed on fresh MCP samples and each detector was used only once, because as a result of these measurements, the detectors lose their sensitivity to a large extent. In this study, a specific thermal treatment intended to fully restore the loss of MCPs TL sensitivity was sought. We have investigated several annealing procedures, applying different temperatures (from 400{\deg}C up to 700{\deg}C) for different periods of time (10-30 minutes) in argon atmosphere. In this way we were able to recover MCP sensitivity fully, allowing for reuse of the samples after high-dose irradiation and high-temperature measurement.