PREPARATION AND INVESTIGATION OF THERMOLUMINESCENCE PROPERTIES OF CASO4-DY,CU

TL dosimetric properties of CaSO4:Dy are advantageous at 0.10-0.2 mol% of Dy concentration. The upper limit of linearity is similar to 1 Gy because of the supralinearity caused by the deep traps. The use of cop per coactivator reduces the deep traps in the crystal and the upper li mit of linearity is increased. The effect of copper on the high temper ature peak (300-350 degrees C) of the glow curve was investigated in t he concentration range 0-0.3 mol% Cu for different Dy concentrations. The phosphor was prepared according to our method in the presence of h ydrogen peroxide. The optimum copper concentration was found to be 0.2 5 mol% Cu at 0.2 mol% Dy. According to the measurements, the upper lim it of linearity is increased by more than one order of magnitude (25-3 0 Gy). Thus the application of CaSO4:Dy,Cu may also be extended to the field of accident dosimetry.