OPTICAL-ABSORPTION AND THERMOLUMINESCENCE IN LIFMG, TI (TLD-100) - DEPENDENCE ON LINEAR-ENERGY-TRANSFER

Thermoluminescence (TL) and optical absorption (OA) studies in LiF TLD -100 single crystals are carried out after thermal neutron and gamma-i rradiations. For thermal neutrons, similar to the TL peak VII (300-deg rees-C) to peak V (225-degrees-C) height ratio, the 250 nm to 310 nm O A band height ratio is quite large as compared to that for gamma-rays. The changes in 250 nm band during peak VII readout reveal that the pr eferential increase in 250 nm OA band for thermal neutrons is associat ed with an increase in peak VII TL only, thereby indicating that the p eculiar LET (linear energy transfer) dependence of peak VII can be a d irect consequence of the two-hit nature of its traps. This conclusion receives further support from the similar LET dependence exhibited by M (448 nm)-centres and peak VII centres in TLD-100. The structure, i.e . the two-hit nature, and the position of OA of M-centres in LiF are a lready well established.