On the draught, height and area of smoke pipes, etc.

Abstract

CaF2:Dy phosphor was prepared by ball milling method over particle size ranging from 140 nm to 35 nm, and their thermoluminescence properties were studied by irradiation with 60Co gamma rays. The XRD revealed that the crystallite size was of ∼45 nm for pristine, 19.1 nm for 10 h and 9.99 nm for 50 h ball-milled phosphor samples and confirmed by FESEM. The UV–visible spectra indicate that the absorption and scattering of radiation increased with a decrease in the particle size along with the blue shift in the absorption peak. CaF2:Dy particles of different sizes were irradiated with gamma dose from 1 Gy to 20 kGy and respective thermoluminescence response was studied. It was observed that the ∼65 nm particle size phosphor showed a linear response with gamma dose range from 1 Gy to 12 kGy. These results reveal that the CaF2:Dy phosphor can be used for high gamma radiation measurement and food irradiation dosimetry.