Structural Study of Plastic Crystals by Use of an Area Detector.

当一种使用光激励荧光屏的X射线面探测器，称为“成像板(IP)”，应用于衍射图是连续的和漫反射的样品的强度测量时，它作为二维探测器显示出极大的用途。首先，面积探测器(DIP100，MAC Science)已被应用于液体CCl_4和H_2O的X射线散射强度测量。并与用能量色散法测得的散射强度进行了比较。用不同的方法得到的光强彼此吻合很好。实验证明，使用激发剂探测器可以用较短的累积时间和简单的分析过程精确地测量晕图的散射强度，并且在高散射角下不受散射X射线斜入射到激发剂的影响。接下来，测量了室温下为塑料晶体的金刚烷单晶的衍射图。它们包含劳厄斑点、各向异性和漫射散射图案。似乎C&lt；10&gt；H&lt；16&gt；分子在面心立方晶格点上发生了较大的振动运动。

When an area detector for X-rays using a photostimulable phosphor screen, called "an imaging plate (IP)", is applied to the intensity measurement of the samples whose diffraction pattern is continuous and diffuse, it exhibits greatly the usefulness as the two-dimensional detector. The area detector is especially indispensable for the intensity measurement of a diffuse and anisotropic diffraction pattern, for example the diffraction pattern from plastic crystals.First the area detector (DIP100, MAC Science) has been applied to the intensity measurements of X-ray scattering from liquids CCl_4 and H_2O. The scattering intensities in the present experiments have been compared with that determined by means of an energy-dispersive method. The intensities obtained by the different methods have agreed well with each other. It has been proved that the use of the IP detector makes it possible to measure the scattering intensities of halo patterns precisely with much shorter accumulating time with a simple procedure of analysis and that there is no effect of the oblique incidence of scattering X-rays to the IP at high scattering angles.Next diffraction patterns from a single crystal of adamantane (C_<10>H_<16>), which is plastic crystal at room temperature, have been measured. They have contained Laue spots and anisotropic and diffuse scattering patterns. It seems that the molecules of C_<10>H_<16> make a large librational motion on the fcc lattice points.