STUDIES AND IMPROVEMENT OF RADIATION-INDUCED COLOR-CENTER DOSIMETER IN LIF

We have studied the properties of the dosimeter which was made of home manufactured LiF crystal. The crystal was cut into chips and each of w hich was 6 mm X 6 mm X 1 mm in size. The value of absorbed dose in LiF was calibrated by alanine/ESR dosimetry. The alanine samples were sup plied and measured by National Institute of Metrology. The irradiation s were carried out with a cobalt-60 source of 7.4 X 10(15) Bq of Tianj in TechnicaL Physics Institute. The dose-effects of absorbance peaks f or F,N,R and N band, in specific dose ranges, can all be expressed as A=bD(n), where A is the increase in average optical absorbance; b and n are constant relating to the type of color-centers and the impurity of the crystal. We also study to anneal the crystal after irradiation, stable time is cut down from 24hr. to 4hr.