High Sensitivity of LiF:Mg,Cu,P Thermoluminescent Dosimeter and Its Application for Low Dose Measurement In Medical Field

The high sensitivity of thermoluminescent dosimeter (TLD) is required in the medical field for measurement of radiation dose for patient and workers who need high accuracy in diagnose. During this time, LiF TLD has become a choice and have dominated its use in determining dose and as quality assurance, especially for LiF:Mg,Cu,P have been applicated to measure low dose radiation, such as accepted dose of pediatric patients and estimation for out of field dose.
It’s also used as extremity dosimeter for determination of eye doses. In addition to many advantages, there are also some disadvantages mainly the decrease in sensitivity due to the heat treatment and it is can cause inaccuate of the doseresponse.Other important variables to be considered are annealing procedure, heating rate, and ROI (region of interest)determination in readout of TLD response. By using the calibrator machine OB-85 with 137Cs as gamma source, the
selected LiF:Mg,Cu,P TLD was exposed on the surface of phantom with 30x30x15 cm dimensions at a distance of 200 cm.
The result of research, in the several cycles use of TLD obtained deviation of sensitivity for each TLD are 7.99 to 15.80% for LiF:Mg,Cu,P, 0.49 to 10.59 % for 6LiF:Mg,Cu,P and 13.07 to 30.46 % for 7LiF:Mg,Cu,P with uniformity of TLD
response lower than 5%.To obtain more accurate and precision measurements with a high confidence level it needto
concern about the uniformity of TLD response and optimization of annealing techniques.