Gager L D, Wright A E, Almond P R
Med Phys. 1977 Nov-Dec;4(6):494-8. doi: 10.1118/1.594348.
Silicon diode detectors have the advantages of high resolution, large signal, and fast response, but lack the flat energy response of the Farmer ion chamber. A study was undertaken to develop a compensating shield for a diode which would make it suitable for use in the spectrum of energies produced by a high-energy radiation beam at depth in a phantom. The energy response of the unshielded diode was quantitated over a range of energies from 18.5 keV to 8 MeV. Shields of different thickness, density, and design were tested experimentally. A partial shield of high-Z material over a diode with miniaturized contacts produced a probe which duplicated the relative dose measurements of the Farmer chamber with less than 1% variation. Typical central axis depth-dose curves and a beam profile, measured with the chamber and the shielded and unshielded probe, are illustrated.
硅二极管探测器具有高分辨率、大信号和快速响应的优点，但缺乏 Farmer 电离室的平坦能量响应。开展了一项研究，以开发一种用于二极管的补偿屏蔽，使其适用于在模体中深处由高能辐射束产生的能量谱。在 18.5 keV 至 8 MeV 的能量范围内对未屏蔽二极管的能量响应进行了定量。对不同厚度、密度和设计的屏蔽进行了实验测试。在具有小型化触点的二极管上使用高 Z 材料的部分屏蔽产生了一种探头，其重复 Farmer 电离室的相对剂量测量，变化小于 1%。展示了用该电离室以及屏蔽和未屏蔽探头测量的典型中心轴深度剂量曲线和射野分布图。
