Coherent transition radiation in the far-infrared region.
Coherent transition radiation in the far-infrared region.
复制标题
远红外区域的相干跃迁辐射。
DOI：
10.1103/physreve.49.785
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
M. Oyamada
中科院分区：
文献类型：
--
作者：
Y. Shibata;K. Ishi;Toshiharu Takahashi;T. Kanai;F. Arai;S. Kimura;T. Ohsaka;M. Ikezawa;Y. Kondo;Ryukou Kato;S. Urasawa;T. Nakazato;S. Niwano;M. Yoshioka;M. Oyamada
从150 MeV电子束通过上游铝箔和下游铝镜组成的辐射系统，在0.2~5 mm的波长范围内观测到相干跃迁辐射。在束流为1µA时，当束流为1 mm时，与非相干Tr相比，强度提高了一倍0.9\ifmmode\times\else\texttimes\fi{}${10}^{6}$。这个因子的值接近于束团中的电子数。观察到反射强度取决于发射长度或电子在箔和反射镜之间的轨迹长度。观察到了光强的角分布及其对波长和发射长度的依赖关系。所有结果均与理论吻合较好。还研究了反射强度对光束横截面和辐射材料的依赖关系。从束流的观测光谱出发，得到束团中电子的纵向分布函数近似为正态分布，束团长度半高宽为0.28 mm。
Coherent transition radiation (TR) has been observed in the wavelength range from 0.2 to 5 mm, which is emitted from bunches of 150-MeV electrons passing through a radiator system composed of an upstream aluminum foil and a downstream aluminum mirror. At the beam current of 1 \ensuremath{\mu}A, the intensity at \ensuremath{\lambda}=1 mm is enhanced by a factor of 0.9\ifmmode\times\else\texttimes\fi{}${10}^{6}$ compared with incoherent TR. The value of this factor is close to the number of electrons in the bunch. The intensity of the TR has been observed to depend on the emission length or the length of the trajectory of the electrons between the foil and the mirror. The angular distribution of the TR intensity and its dependence on the wavelength and on the emission length have been observed. All results are in good agreement with theory. Dependences of the TR intensity on the cross section of the beam and on the radiation material have also been examined. From the observed spectrum of TR, the longitudinal distribution function of electrons in the bunch is derived to be approximately a Gaussian with the bunch length full width at half maximum of 0.28 mm.