STUDY OF COHERENT SYNCHROTRON RADIATION AND CHERENKOV RADIATION

来自直线加速器的电子被限制在一个纵向长度为几毫米的短束中。在我们的研究中，我们使用了东北大学核科学实验室和京都大学研究反应堆实验室的线性加速器来观察相干同步辐射。在这两种情况下，观测到的光谱在波长约1至4毫米处有一个峰值，强度比普通辐射增强了几个数量级。强度与光束电流和辐射极化的关系与理论一致。在研究过程中，我们首次观察到电子穿过薄金属箔时发出的相干跃迁辐射。由于相干效应，其光谱和强度的增强与相干同步辐射相似。光强随发射长度的变化规律和光强的角分布规律与理论基本一致。此外，我们还利用大阪大学的直线加速器观测到了相干跃迁辐射。我们已经确定了光束的直径和发射度，以及一束电子的纵向分布。相干跃迁辐射已被证明是一种有效的光束诊断手段。因此，用相干辐射研究了长波区跃迁辐射的性质。相干跃迁辐射和同步辐射已被证实是有用的连续光谱源。我们已经指出，在切伦科夫辐射来自电子有界轨迹的情况下，区分跃迁辐射和切伦科夫过程的贡献是很重要的。此外，我们还通过实验证实，为了发生切伦科夫过程的有效辐射，发射长度必须大于形成区。少

The electrons from a linear accelerator is confined in a short bunch whose longitudinal length is a few millimeters. In our study we have used linear accelerators at laboratory for Nuclear Science, Tohoku University and at Research Reactor Laboratory, Kyoto University to observe coherent synchrotron radiation. The observed spectrum in either case had a peak at a wavelength around 1 to 4 mm and the intensity was enhanced by a factor of several orders of magnitude compared with that of ordinary radiation. The dependence of the intensity on the beam current and the polarization of the radiation were in agreement with theory. During the study, we observed for the first time coherent transition radiation which was emitted when the electrons passed through a thin metallic foil. Its spectrum and the enhancement of the intensity due to the coherent effect ware similar to those of the coherent synchrotron radiation. The dependence of the intensity on the emission length and the angular distribu … More tion of the intensity were in accordance with theory. Further, we have observed coherent transition radiation using a linear accelerator at Osaka University. We have determined the diameter and the emittance of the beam, and the longitudinal distribution of the electrons in a bunch. Coherent transition radiation has been proved to be a useful means of the beam diagnosis. Thus, the properties of transition radiation in the long wavelength region have been studied by the coherent radiation. Coherent transition radiation and synchrotron radiation have been confirmed to be useful sources with continuous spectra.We have pointed out that it is important to distinguish the contribution from the transition radiation from that of the Cherenkov process in the case of the Cherenkov radiation from a bounded trajectory of the electron. Further, we have confirmed experimentally that the emission length must be longer than the formation zone in order that effective radiation of the Cherenkov process occurs. Less