Dependence of Probability for Excitation on the Distance from the Crystal-Plane and Surface Derived by Using the Channeling of Hydrogens

在实验装置方面，将散射室和离子泵更换为较大的散射室。烘烤后，10^lt；-10；10；Torr的超高真空度变得很容易获得。准备了一支Ar溅射离子枪，并将其安装到燃烧室中，在它们之间放置了一个闸阀。使溅射后残留的Ar气体能够快速排出。识别样品；制备了Al外延膜，并用透射电子显微镜进行了观察。其中一些材料可用于后续的沟道实验。针对样品表面的清洗，用离子枪产生的Ar束对样品表面进行溅射。为了保持真空度，在高真空中溅射了铝的氧化层。然后，在超高真空中溅射几层单分子膜。针对主要实验，奈良女子大学加速器的MeV H~(++)离子束在沟道条件下入射到铝箔上。薄片被放置在特高压室中，几乎垂直于入射光束方向，并与入射光束方向成30°的角度测量。测得的离子沟道的中性分数比随机离子的测量的中性分数要低。除了交换衬底外，还测量了沟道效应的能量依赖性。与理论计算相一致，利用离子轨迹计算了沟道离子的中性分数。将表面原子的散射效应应用到计算中，得到了与实验结果相一致的结果。

Concerning the experimental apparatus; the scattering chamber and the ion pump were replaced with somewhat large ones. The ultra-high vacuum of 10^<-10> Torr becomes easily available after baking of the chamber. An Ar-sputtering ion-gun was prepared and installed to the chamber putting a gate-valve between them. The rapid evacuation of the residual Ar gas after the sputtering was made possible.Concerning the sample; epitaxial foils of AI were prepared and observed by a transmission electron microscope. Some of them can be used in the following channeling experiment.Concerning the cleaning of the sample-surface; the sputtering of the surface by the Ar beam from the ion-gun was carried out. In order to maintain the vacuum, the oxide-layer of the AI was sputtered in a high vacuum. Thereafter, a few monolayer were sputtered in the ultra-high vacuum.Concerning the main experiment; a MeV H^+-ion beam from the accelerator of the Nara Women's University was impinged on the AI foil under a channeling condition. The foils were placed in the UHV chamber to be almost perpendicular to, and with the angle of 30° measured from, the incident beam direction. The measured neutral fractions for channeling through ions were decreased compared with those measured for random ions. The energy dependence of the channeling effect was also measured in addition to the exchanging foils. It was found that the energy dependence of the two angles of foils was different from each other.Concerning the theoretical calculation; the neutral fraction of the channeling-ions was calculated with the ion trajectories. By applying an effect of scattering at the atoms on the surface to the calculation, a good agreement with the experimental results was obtained.