Comparison and development of advanced dosimetric techniques to be used under extreme climatic conditions

The post-irradiation fading characteristics of various dosimeters in function of relative humidity of air during storage were tested in specially set up humidity boxes. The temperature and relative humidity were varied between 5deg-35degC and 40-90%, respectively. Fading was 70% and 80% at 2 and 6 days respectively, for Kodak Type 2 film under 28degC and 76% relative humidity. Under these conditions the corresponding values for NTA emulsions were 30% and 80% respectively. Agfa-Gevaert films proved to be less sensitive and gave 20% and 30%, respectively, for the mentioned intervals. When Kodak Type 2 film was sealed in polythene bags, fading was reduced considerably, to appr. 15% in 4 weeks. Alternate storage of exposed films in humid and dry conditions also reduced fading to the same extent. When NTA emulsions were double-sealed with desiccant inside fading was reduced to 10% in 15 days. CaSO4:Dy (DRP and Harshaw) showed only 7% fading in 3 months. LiF TLD-100 was more sensitive, 13% in 2 months. Gamma-irradiated Li-borate has faded up to 30% at extreme climatic conditions in 3 months but thermal neutron irradiated Li-borate was resistant against fading for this period