Sensitised TLD-700 for neutron-gamma ray dosimetry at radiation protection dose levels

Computerised glow curve deconvolution (CGCD) has been used to study the TL dose response and the relative intensity of the high temperature peaks in both sensitised and 'as received' LiF:Mg,Ti (TLD-700). The 60Co gamma induced dose response of peak 7 is supralinear down to the lowest dose measurable (∼ 2.5 mGy) and the supralinearity is strongly dependent on photon energy. In the sensitised material (the sensitisation procedure included 1000 Gy 60Co irradiation followed by a 3400C, 30 min anneal), although the gamma induced dose response of peak 7 is linear, an intense high temperature background limits the minimum measurable dose to 500 μGy and 100 μGy for gamma and neutron irradiation respectively. We conclude that the method of peak 7/peak 5 ratios in both non-sensitised and sensitised TLD-700 is not suitable for neutron-gamma ray dosimetry at personal radiation protection dose levels. (author)