Thermoluminescence Characteristics of CaSO4 Doped with Dy and Cu

The effect of copper (Cu2+) co-doping on the thermoluminescence characteristics of CaSO4:Dy has been investigated. The addition of copper is found to suppress effectively the high temperature peak structure of CaSO4:Dy centred around 350 oC which in the absence of copper, conspicuously builds up with dose. Increased copper concentration affects the glow curve preferentially in the high temperature region. This makes the glow curve of CaSO4:Dy, Cu relatively narrower with a small reduction in TL sensitivity (about 10% at 0.1 mol % of Cu). The addition of copper significantly extends the region of linearity of the TL against dose response curve from 1 Gy for CaSO4:Dy to about 10-102 Gy for CaSO4:Dy, Cu depending upon copper concentration. With appropriate copper concentration ((0.2 mol %), CaSO4:Dy, Cu could also become a sensitive TLD material for UV dosimetry. In view of some of these favourably augmented TL features CaSO4:Dy, Cu with desired copper concentration becomes an interesting material for conventional as well as laser stimulated TL dosimetric systems.