Drost D J, Mehuys D, Fenster A
Med Phys. 1984 Sep-Oct;11(5):610-7. doi: 10.1118/1.595622.
In a companion paper, we reported on the construction and testing of a xenon gas ionization detector for use in line scanned projection radiography. Experimental results indicate that the detector has sufficient resolution for chest radiography, but higher resolution is required for mammography. Theoretical analysis suggested that a detector pressurized with Freon 13B1 would have better resolution and higher x-ray energy efficiency than a xenon-filled detector for energies below 60 keV. In this paper we compared, theoretically and experimentally, Freon 13B1 to xenon as the detector gas. For a 120-kVp x-ray spectrum, the detector filled with 2.0 MPa of xenon had less channel-to-channel crosstalk, a higher quantum efficiency (QE), and twice the output signal than the detector filled with 1.4 MPa of Freon (highest possible pressure at room temperature), while for a 60-kVp spectrum, crosstalk is the same, but the detector has slightly higher QE and 1.4 times the energy efficiency when filled with Freon instead of xenon. We conclude that xenon is better for high-kVp imaging, while Freon at a lower pressure is slightly better for low-kVp imaging.
在一篇配套论文中，我们报道了一种用于线扫描投影射线照相术的氙气电离探测器的构建与测试。实验结果表明，该探测器对于胸部射线照相具有足够的分辨率，但对于乳腺摄影则需要更高的分辨率。理论分析表明，对于能量低于60keV的情况，用氟利昂13B1加压的探测器比填充氙气的探测器具有更好的分辨率和更高的X射线能量效率。在本文中，我们从理论和实验两方面将氟利昂13B1与氙气作为探测器气体进行了比较。对于120kVp的X射线光谱，填充2.0MPa氙气的探测器比填充1.4MPa氟利昂（室温下的最高可能压力）的探测器具有更低的通道间串扰、更高的量子效率（QE）以及两倍的输出信号，而对于60kVp光谱，串扰相同，但填充氟利昂而非氙气时，探测器具有略高的QE和1.4倍的能量效率。我们得出结论，氙气更适合高kVp成像，而较低压力下的氟利昂对于低kVp成像略好。
