Dose re-estimation by method in TLD

The Effects of Photon Energy and Irradiation History on the Efficiency of Dose Re-Estimation in CaSO₄:Dy Teflon Discs Using Repeated Read-outs

1. A.R. Lakshmanan and 
2. R.C. Bhatt

Abstract

Since Teflon is a bad conductor of heat, in many readers the thermoluminescence of a CaSO₄ Teflon TLD disc is erased only partially during the first read-out; the second and even the third TL read-outs are functions of the absorbed dose. This offers a simple method of re-estimation of absorbed dose. The present study has shown that, as might be expected, the efficiency of dose re-estimation by the above method in CaSO₄:Dy Teflon TLDS, is independent of the photon energy of the incident radiation in the range 30 keV - 1.25 MeV as well as of the irradiation history. Annealing at 240 ^oC was found to restore the original as well as the re-estimated TL sensitivity after a gamma dose of 0.12 Gy. This is unlike the case with PTTL technique in LiF. The above differences arise because in the first method, the re-estimated TL is still a characteristic of dosimetry traps whereas the PTTL is a characteristic of deep traps.

• Radiation Protection Dosimetry

Source: http://rpd.oxfordjournals.org/content/1/2/125