Comparison of commercial thermoluminescent readers regarding high-dose high-temperature measurements

摘要

Three different thermoluminescent measuring systems have been compared withrespect to the differences in temperature profiles, spectral sensitivities, aswell as linearity of dose response characteristics. The comparison wasperformed using the Harshaw 3500, Riso DA-20 and RA94 TLD readers. Theinstruments were tested for the readouts of highly irradiated LiF:Mg,Cu,P (MCP)TL detectors, which require readout up to 550 C, in case of doses exceeding 1kGy. It was found that the Harshaw 3500 can be used, without any additionallight attenuation, for the measurements of MCP detectors exposed to doses up toabout 5 Gy. For the other two readers the upper dose limit is about 5 timeslower. It was also found that the Harshaw 3500 shows the best thermal stabilityconsidering the peak maximum position. For the ultra-high doses the differencesin the spectral characteristics of the applied optical filters andphotomultipliers, in conjunction with an evolution of the MCP TL emissionspectrum with increasing dose, significantly influence the shape of TL glowcurves measured with the Riso reader. The detailed characteristic of thecompared TLD readers, at high-dose high-temperature range is discussed.