Effect of the Cu co-activator on the charge-carrier trapping efficiency in CaSO4:Tm,Cu

• Two series of CaSO4:Tm,Cu of different amount of dopant were synthesized.
• Consecutive radioluminescence and thermoluminescence measurements were carried out.
• Light yields R and T of both process determined.
• The efficiency of trapping Q = T/(R + T) was calculated.
• The connection between Cu concentrations and the Q values was investigated.

Rare earth doped CaSO4 materials are well known thermoluminescent dosimeters with friendly properties. They are used in the practice for a long while. New phosphors based on CaSO4:Tm were synthesized using a modified preparation method for adding Cu as co-dopant. The produced materials have several favorable new characteristics. Larger linear dose response range, simpler glow-curve structure and a small diminution in the sensitivity are the consequences of the copper addition. Trapping efficiency of samples containing different amounts of Tm and Cu was investigated as the function of the composition using a consecutive RL/TL measuring technique. It was cleared up that the Cu addition, depending on its amount, reduced this value. This plays the main role in the sensitivity loss and forms one of the factors in the explanation of the linear dose range widening.