Calibration of TLD in Eye Lens Dosimeter Hp (3) using wide Energy X-ray

The objectives of this study was to calibrate the EYE - D TM holder with MCP - N (LiF : Mg , Cu and P) PTW detector for personal dose equivalent in depth of 3 mm tissue equivalent in wide X - ray energy range using circular head PMMA equivalent Phantomof 20 cm × 20 cm × 1.2 cm. Six sets of eye lens dosimeters containing thermoluminescence dosimeters (TLD) MCP - N (LiF : Mg , Cu and P) irradiated by using a Xstrahl machine with following operating conditions : 100 cm FSD, 1 mA, irradiation time 1 min., 0.2 mm HVL (Al) and energies of 50 kV, 80 kV, 100 kV, 120 kV and 150 kV, respectively. Each TLD set irradiated for specific air kerma corresponding to each of considered energies, theair kermarang - ingfrom 2.3mGy to 6.6 mGy. The absorbed doses measured by Unidose meter connected with a 0.2 cc soft X - ray ionization chamber . The ratio between calculated H p (3) of eye lens doses and TLD reader Harshaw 3500 response are to be calculated to determine the reader calibration factor. The air kerma doses were converted to H p (3) using conversion coefficients available from published literature. An individual calibration for each X - ray energy carried out and a direct method for measurement of equivalent dose in term of H p (3) investigated .