Aoki K, Koyama M
Department of Radiology, Komazawa Junior College, Tokyo, Japan.
Phys Med Biol. 1990 Nov;35(11):1505-17. doi: 10.1088/0031-9155/35/11/006.
A silicon detector which can be used like a thimble chamber has been constructed. The silicon diode chip used here is very small (1.7 x 1.7 x 0.1 mm3), and the construction materials of the detector mount are thin and have low atomic numbers. Thus, the characteristic x-rays from the mount give no distortion on the obtained spectra, and the photons incident on the back surface of the silicon chip can be measured. Furthermore, the perturbation of the x-ray field is small. The energy resolution of the detector is 2.0 keV (full width at half maximum) for 59.5 keV photons at room temperature. Bremsstrahlung spectra (60-100 kV, 1-2 mA) have been measured without using a pinhole collimator; the obtained spectra are in good agreement with those obtained with a Ge detector. The spectrum of the radiation in a water phantom irradiated with 90 kV x-rays has also been measured by inserting the detector in the phantom; the obtained scattered spectrum has been corrected for the angular dependence of detector efficiency. The increase in total photon number due to this correction has been found to be below 2%.
已制造出一种可像指形电离室那样使用的硅探测器。这里使用的硅二极管芯片非常小（1.7×1.7×0.1立方毫米），探测器支架的构造材料很薄且原子序数低。因此，支架产生的特征X射线不会使所获光谱产生畸变，并且可以测量入射到硅芯片背面的光子。此外，X射线场的扰动很小。在室温下，该探测器对于59.5keV光子的能量分辨率为2.0keV（半高宽）。在不使用针孔准直器的情况下测量了轫致辐射光谱（60 - 100kV，1 - 2mA）；所获光谱与用锗探测器获得的光谱吻合良好。通过将探测器插入水模体中，还测量了用90kV X射线照射的水模体中的辐射光谱；已对所获散射光谱进行了探测器效率角度依赖性的校正。已发现由于这种校正导致的总光子数增加低于2%。
