Department of Biomedical Engineering, University of Tennessee-Memphis, Memphis, Tennessee 38163.
J Xray Sci Technol. 1995 Jan 1;5(2):228-47. doi: 10.3233/XST-1995-5206.
Gas ionization x-ray detectors operating at pressures up to 100 atm offer inherently high spatial and contrast resolution. However, incorporating the detector x-ray entrance window in a conventional pressure vessel designed for such pressures can result in high primary beam loss in the window and a much reduced overall detective quantum efficiency. The design of a gas chamber cover plate for a strip beam detector which mechanically isolates the x-ray entrance window from the lateral tensile stresses in the chamber body is described. A number of test windows of this design, varying in three geometric parameters-thickness, window curvature, and fillet radius-were fabricated from wrought aluminum [6061-T651 ] and subjected to pressures of up to 400 atm for the purpose of selecting an optimum window for a prototype digital x-ray imaging detector. The experimental data indicate that windows can be designed for a detector admitting a 1.0 cm wide x-ray beam that have rupture pressures exceeding 500 atm while maintaining x-ray transmittances of as much as 93.4% for a 120 kVp tungsten anode spectrum.
工作压力高达 100 大气压的气体电离 X 射线探测器具有固有高的空间和对比度分辨率。然而，在为这种压力设计的传统压力容器中加入探测器 X 射线入口窗，会导致窗口中初级光束的大量损失，并大大降低整体探测量子效率。本文介绍了一种用于条带束探测器的气体室盖板的设计，该设计通过机械方式将 X 射线入口窗与腔室体的横向拉伸应力隔离开来。这种设计的多个测试窗口，在厚度、窗口曲率和圆角半径三个几何参数上有所不同，由锻造铝合金[6061-T651]制成，并承受高达 400 大气压的压力，目的是为原型数字 X 射线成像探测器选择最佳窗口。实验数据表明，可以为探测器设计工作压力超过 500 大气压的窗口，允许通过 1.0 厘米宽的 X 射线束，同时保持对于 120 kVp 钨阳极谱的 93.4%的 X 射线透过率。
