DAP(Dose Area Product)를 이용한 TLD와 PLD의 선량 측정 비교

Abstract

본 연구는 현재 법령 개인선량계인 PLD와 TLD의 선량 분석을 통해 성능 차이를 알아보고자 하였다. 자동판독장치를 이용해 PLD와 TLD의 적산선량을 판독 후 선량 교정 과정을 거친 두 소자의 값은 70kVp, 200mA, 0.012sec와 42kVp, 100mA, 0.012sec의 각각의 촬영조건에서 TLD는 PLD 측정 시와 통계적 차이를 나타냈다(각각 p<0.001, p<0.001). DAP와 두 소자의 측정값 차이는 70kVp, 200mA, 0.012sec 촬영조건에서 TLD는 DAP 평균값보다 <TEX>$44.2mGy{\cdot}cm^2$</TEX>이 낮은 값이 나타났고, PLD는 DAP 평균값에 <TEX>$15.5mGy{\cdot}cm^2$</TEX>이 낮은 <TEX>$246.8mGy{\cdot}cm^2$</TEX>으로 나타났다. 42kVp, 100mA, 0.012sec 촬영조건에서는 TLD는 DAP 평균 값의 <TEX>$17.9mGy{\cdot}cm^2$</TEX>이 낮은 값을 보였으며, PLD는 DAP 평균값에 <TEX>$7.6mGy{\cdot}cm^2$</TEX>이 낮은 <TEX>$82.6mGy{\cdot}cm^2$</TEX>으로 나타나 PLD가 DAP에 더 근접한 값을 보였다. 또한 PLD에 비해 TLD는 10개의 각 소자마다 측정된 선량 값에서 소자 상호간의 편차가 크게 나타났고, 1개의 소자를 반복 측정한 재현성 실험에서 PLD는 <TEX>${\pm}1%$</TEX> 이내로 TLD <TEX>${\pm}2%$</TEX> 보다 낮게 나타났다. 따라서 PLD가 TLD에 비해 선량 측정 능력면에서 더 우수한 결과가 나타났고, 진단용 방사선영역에서 방사선작업종사자의 개인피폭 관리에 PLD가 더욱 적합하고 유리함을 확인할 수 있었다. The results of analyzing the difference between performances of individual dosimeters on this research subjecting the PLD and TLD, which are the official personal dosimeters, through dosimetry are as follows. After scanning the integral dose using an automatic scanner, the values of two devices that went through dose adjustment process had a statistical difference in TLD and PLD measurements under each filming conditions which were 70kVp, 200mA, 0.012sec and 42kVp, 100mA, and 0.012sec (p<0.001 and p<0.001 respectively). As for the difference of measurement value between DAP and the two particles under 70kVp, 200mA, 0.012sec filming condition, TLD had a value lower than DAP average value by <TEX>$44.2mGy{\cdot}cm^2$</TEX> and PLD had a value of <TEX>$246.8mGy{\cdot}cm^2$</TEX> which was lower than DAP average value by <TEX>$15.5mGy{\cdot}cm^2$</TEX>, while under 42kVp, 100mA, 0.012sec filming condition, TLD had a value lower than DAP average value by <TEX>$17.9mGy{\cdot}cm^2$</TEX> and PLD had a value of <TEX>$82.6mGy{\cdot}cm^2$</TEX> which was lower than DAP average value by 7.6<TEX>$mGy{\cdot}cm^2$</TEX>. Also, compared to PLD, each of 10 devices measured dose value in TLD had a larger deviation between the particles, and for a reproducibility test which repeatedly measured one particle, PLD had <TEX>${\pm}1%$</TEX> which was lower than TLD's <TEX>${\pm}2%$</TEX>. As such, PLD had a superior performance result in dose measurement capacities aspect compared to TLD, and therefore we could verify that PLD is more appropriate and advantageous in managing radiation-related task performing worker's personal radiation exposure management in the diagnostic radiation field.