Thermoluminescence characteristics and dose responses in MgSO5 : Dy, P andMgSO4 : Dy, P, Cu phosphors

The MgSO4:Dy, P and MgSO4:Dy, P,Cu phosphors have been developed and studie d by the thermoluminescence (TL) glow curves and dose responses to gamma ra diation. The TL sensitivity of MgSO4:Dy, P phosphor is higher than that of LiF:Mg, Ti. One main dosimetric peak at about 283.6 degrees C and a satelli te peak at about 352.7 degrees C are involved in the TL glow curve of the M gSO4:Dy, P which was measured with a heating rate of 5 degrees C s(-1) and deconvoluted by the general order kinetics equation to obtain the peak para meters and trap parameters of the elementary TL peaks. The dose responses t o gamma rays in the dose range from 0.1 Gy to 20 kGy were obtained and fitt ed by the composite action dose response function to get the nonlinear char acteristic parameters, one-hit factor R and characteristic dose D-0, which indicate that the TL dose responses for the two peaks of MgSO4:Dy, P are su pralinear. When a trace amount of Cu was co-doped into MgSO4:Dy, P the TL g low peak at 352.7 degrees C was suppressed and the TL sensitivity and the n onlinearity of dose response for the main dosimetric peak at 283.6 degrees C critically depends on the concentration of doped Cu. The dose response of MgSO4:Dy, P,Cu (0.1 mol%, 0.5 mol%, 0.01 mol%) phosphor is linear-sublinea r. The MgSO4:Dy, P,Cu (0.1 mol%, 0.5 mol%, 0.004 mol%) phosphor has a wider linear range in the dose response than MgSO4:Dy, P (0.1 mol%, 0.5 mol%) an d its TL sensitivity is close to MgSO4:Dy, P (0.1 mol%, 0.5 mol%). It may b e a candidate with which to measure radiation dose under higher dose circum stances.