Energy dependence of commercially available diode detectors for in-vivo dosimetry
Energy dependence of commercially available diode detectors for in-vivo dosimetry
复制标题
DOI：
10.1118/1.2719365
复制
发表时间：
2007-05-01
期刊：
影响因子：
3.8
通讯作者：
Zhu, Timothy C.
中科院分区：
文献类型：
--
作者：
Saini, Amarjit S.;Zhu, Timothy C.
在Co-60和17 mV的标称加速电势范围内，测量了商用二极管探测器的能量依赖性。测量是在液态水模型中进行的，深度为5 cm，准直器设置为10×10 cm(2)，源到探测器的距离为100 cm。在对每个二极管的剂量率和温度依赖关系进行校正后，对Co-60射线的响应(Nc/Gy值)进行归一化。通过取归一化到Co-60束的最大和最小灵敏度之间的百分比差来计算能量依赖关系，对于在Co-60和17 mV之间的标称加速电势，n型异质结红、n型异质结电子、QED红(p型)、QED电子(p型)、QED蓝(p型)的变化幅度分别为39%、26%、19%、15%、11%和6%。Isorad-3 Gold#1和#2的差异为34%，Veridose Green的差异为35%，Veridose黄的差异为15%，Veridose电子的差异为9%，n型QED Gold的差异为2.1%，n型QED Red的差异为24%，EDP2(3G)的差异为3%，PFD(光子场探测器)的差异为2%，EDP10(3G)的差异为7%，EDP20(3G)的额定加速电位为16%。通过蒙特卡罗模拟验证了能量依赖性的大小。我们得出的结论是，能量依赖关系不取决于二极管是n型还是p型，而主要取决于芯片周围的材料，如积层和积层材料的几何形状。因此，根据实际几何形状，每个二极管的能量依赖值可能会有所不同，因此应谨慎使用。(C)2007年美国医学物理学家协会。
The energy dependence of commercially available diode detectors was measured for nominal accelerating potential ranging between Co-60 and 17 MV. The measurements were performed in a liquid water phantom at 5 cm depth for 10 X 10 cm(2) collimator setting and source-to-detector distance of 100 cm. The response (nC/Gy) was normalized to Co-60 beam after corrections for the dose rate and temperature dependences for each diode. The energy dependence, calculated by taking the percent difference between the maximum and minimum sensitivity normalized to Co-60 beam, varied by 39% for the n-type Isorad Red, 26% for the n-type Isorad Electron, 19% for the QED Red (p-type), 15% for the QED Electron (p-type), 11% for the QED Blue (p-type), and 6% for the EDP10 diode for nominal accelerating potential between Co-60 and 17 MV. It varied by 34% for the Isorad-3 Gold #1 and #2, 35% for the Veridose Green, 15% for the Veridose Yellow, 9% for the Veridose Electron, 2 1 % for the n-type QED Gold, 24% for the n-type QED Red, 3% for the EDP2(3G), 2% for the PFD (photon field detector), 7% for the EDP10(3G), and 16% for the EDP20(3G) for nominal accelerating potential between Co-60 and 15 MV. The magnitude of the energy dependence is verified by Monte Carlo simulation. We concluded that the energy dependence does not depend on whether the diode is n- or p-type but rather depends mainly on the material around the die such as the buildup and the geometry of the buildup material. As a result, the value of the energy dependence can vary for each individual diode depending on the actual geometry and should be used with caution. (c) 2007 American Association of Physicists in Medicine.