Development of an algorithm for TLD badge system for dosimetry in the field of X and gamma radiation in terms of Hp(10).
In view of the introduction of International Commission on Radiation Units and Measurements operational quantities Hp(10) and Hp(0.07), defined for individual monitoring, it became necessary to develop an algorithm that gives direct response of the dosemeter in terms of the operational quantities. Hence, for this purpose and also to improve the accuracy in dose estimation especially in the mixed fields of X ray and gamma, an algorithm was developed based on higher-order polynomial fit of the data points generated from the dose-response of discs under different filter regions of the present TL dosemeter system for known delivered doses. Study on the response of the BARC TL dosemeter system based on CaSO(4):Dy Teflon thermoluminescence dosemeter discs in the mixed fields of X and gamma radiation was carried out to ensure that the accuracies are within the prescribed limits recommended by the international organisations. The prevalent algorithm, based on the ratios of the disc response under various filters regions of the dosemeter to pure photons, was tested for different proportion of two radiations in case of mixed field dosimetry. It was found that the accuracy for few fields is beyond the acceptable limit in case of prevalent algorithm. The new proposed algorithm was also tested in mixed fields of photon fields and to pure photon fields of varied angles. It was found that the response of the dosemeter in mixed fields of photons and its angular response are satisfactory. The new algorithm can be used to record and report the personal dose in terms of Hp(10) as per the international recommendation for the present TL dosemeter.
Bakshi
A K
AK
Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai 400 085, India. akbakshi123@yahoo.com
Srivastava
K
K
Varadharajan
G
G
Pradhan
A S
AS
Kher
R K
RK
D000465:Algorithms; D002133:Calcium Sulfate; D004867:Equipment Design; D005720:Gamma Rays; D006801:Humans; D011829:Radiation Dosage; D011834:Radiation Monitoring / Q000295:instrumentation* / Q000592:standards; D012542:Scattering, Radiation; D013819:Thermoluminescent Dosimetry / Q000295:instrumentation* / Q000592:standards; D014965:X-Rays
D002133:Calcium Sulfate