Studies on hot gas TLD badge reader used in personnel monitoring in India

In our country wide personnel monitoring programme around 58000 radiation workers are monitored using locally made CaSO4:Dy Teflon embedded thermoluminescent dosimetry (TLD) badge system. The automatic hot gas readers also developed locally are used in thermoluminescence (TL) measurements. The reader system has many advantages over the manual reader used earlier and has completely replaced the manual reader system in all TLD personnel monitoring units in India. In the present study the hot gas TLD badge reader system is studied. It has been found that heat capacity of the heating gas, which is responsible for the transfer of heat has a role in deciding the position of glow peak and is verified experimentally using different gas flow rates of nitrogen and argon as heating gases in the reader. The study may also be helpful in fitting the experimentally obtained glow curves and the elimination of unwanted non-radiation induced contributions, namely dark current, electronic spikes, light leakage and triboluminescence etc., which generally distort the glow curve shape, can be achieved. (author)