A comprehensive study on the photon energy response of RadFET dosimeters using the PENELOPE Monte Carlo code
A comprehensive study on the photon energy response of RadFET dosimeters using the PENELOPE Monte Carlo code
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使用 PENELOPE 蒙特卡罗代码对 RadFET 剂量计的光子能量响应进行综合研究
DOI：
10.1080/10420150.2015.1010167
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发表时间：
2015
影响因子：
1
通讯作者：
E. Yılmaz
中科院分区：
文献类型：
--
作者：
A. Kahraman;S. Kaya;A. Jaksic;E. Yılmaz
具有SiO2栅极电介质的辐射传感场效应晶体管（RadFET或MOSFET剂量计）已在太空、放射治疗诊所和高能物理实验室中得到应用。更敏感的RadFET，这需要在设备设计，包括栅极电介质的修改，正在考虑个人剂量测定应用。本文介绍了一个详细的研究结果的RadFET的能量响应与PENMENTAL PE Monte Carlo代码模拟。研究了SiO2的替代材料，以开发高效的新型辐射传感器。也就是说，除了SiO2，Al2O3和HfO2被模拟为栅极材料，并且对于能量在20 keV和5 MeV之间的光子照射，确定这些层中的沉积能量。 模拟进行了加盖和uncapped配置的设备照射的点和扩展源，其表面积是相同的RadFET。使用碰撞探测器估计透射和后向散射光子的能量分布，以提供有关几何结构内粒子通量的信息。记录RadFET材料区中的吸收能量值。对于中低能量的光子，在模拟结果的基础上，讨论了影响不同栅材料吸收能量值的物理过程。结果表明，HfO2是最有前途的模拟栅材料。
Radiation-sensing Field Effect Transistors (RadFETs or MOSFET dosimeters) with SiO2 gate dielectric have found applications in space, radiotherapy clinics, and high-energy physics laboratories. More sensitive RadFETs, which require modifications in device design, including gate dielectric, are being considered for personal dosimetry applications. This paper presents results of a detailed study of the RadFET energy response simulated with PENELOPE Monte Carlo code. Alternative materials to SiO2 were investigated to develop high-efficiency new radiation sensors. Namely, in addition to SiO2, Al2O3 and HfO2 were simulated as gate material and deposited energy amounts in these layers were determined for photon irradiation with energies between 20 keV and 5 MeV. The simulations were performed for capped and uncapped configurations of devices irradiated by point and extended sources, the surface area of which is the same with that of the RadFETs. Energy distributions of transmitted and backscattered photons were estimated using impact detectors to provide information about particle fluxes within the geometrical structures. The absorbed energy values in the RadFETs material zones were recorded. For photons with low and medium energies, the physical processes that affect the absorbed energy values in different gate materials are discussed on the basis of modelling results. The results show that HfO2 is the most promising of the simulated gate materials.