Thermoluminescent response of the mixture of CaSo4(Mn) and Li2SO4 to thermal neutrons and gamma-ray fields

Thermoluminescent responses of the mixtures of CaSO4(Mn) and natural and enriched Li2SO4 to thermal neutrons and gamma-rays have been studied. The response of CaSO4 (Mn, Li) to gamma-ray increases slightly and then decreases as the molar fraction, x, of Li2SO4 increases. The response to the mixed field increases more prominently than that to the gamma-ray field as × increases. The dependence of the response on × is analyzed and it is shown that the thermoluminescent response to thermal neutrons is caused by 6Li(n, alpha)3H reaction. The dosimeter CaSO4(Mn, enriched 6Li) is found to be about 10 times more sensitive than Harshaw TLD-600 (6LiF) and is used to separate the gamma-ray and neutron fields from the mixed field. The ratio of the sensitivity to gamma-ray, to that to thermal neutrons are found to be 1 × 10−8 rad/n/cm2 for CaSO4(Mn, natural Li), and 10.5 × 10−8 rad/n/cm2 for CaSO4(Mn, enriched 6Li). It is suggested that a dosimeter that can give rem values for the mixed field of gamma rays and thermal neutrons can be prepared by adjusting the concentration of 6Li.