Characterization of Lithium Fluoride thermoluminescent detector dose response in the Harshaw 5500 reader for high gamma dose

When using lithium fluoride thermoluminescent detectors (TLDs), the dose response is usually linear up to doses of the order of 1 Gy. However, doses higher than this can be recorded. The effect on the linearity of the TLD-type (MCP-N, MTS-100, and MTT-100) and readout speed (10°C/s and 1°C/s) for a dose range of 0,05 to 50 Gy is evaluated. For MCP, at 1°C/s a dose response is linear within an uncertainty up to 10 Gy, at 10°C/s only to 1 Gy. From 10 Gy, the photomultiplier became saturated. For MTS and MTT, the 10°C/s was slightly more accurate than the 1°C/s readout. The MTS dose response shows linear behavior up to 3 Gy. The MTT dose response only shows linear behavior up to 0.5 Gy. Correction factors for the protocols used at SCK CEN are suggested. A GlowFit analysis gave a better result for the MTT-type.