Masaki Mitsuhiro, Takano Shiro
Japan Synchrotron Radiation Research Institute, SPring-8, Mikazuki, Hyogo 679-5198, Japan.
J Synchrotron Radiat. 2003 Jul 1;10(Pt 4):295-302. doi: 10.1107/s0909049503007106. Epub 2003 Jun 24.
A two-dimensional visible synchrotron light interferometer has been developed to measure the transverse profile of an electron beam at the SPring-8 storage ring. The new interferometer enables the simultaneous measurement of beam sizes along the major and minor axes and the beam-tilt angle of an assumed elliptical Gaussian distribution. The principle of the interferometer is explained through basic formulae. To calibrate the point-spread function of the interferometer, a simple error model was assumed for disturbances in the amplitude and phase of the light; these disturbances were presumably caused by optical elements, such as mirrors and lenses. The experimental method to determine the parameters in the error model is shown. To verify the two-dimensional profiling capabilities of the interferometer, an electron beam stored in the SPring-8 storage ring operated at various working points was observed. A beam broadening from 20 to 120 microm in the vertical direction and changes in the beam-tilt angle were clearly observed at working points close to the differential resonance. However, the vertical spatial resolution is limited by the available vertical separation of the apertures of the diffracting mask because of the narrow aperture of the upstream vacuum duct.
已开发出一种二维可见同步加速器光干涉仪，用于测量SPring - 8储存环中电子束的横向轮廓。这种新型干涉仪能够同时测量沿椭圆高斯分布的长轴和短轴方向的束斑尺寸以及束倾斜角。通过基本公式解释了干涉仪的原理。为了校准干涉仪的点扩散函数，针对光振幅和相位的干扰假设了一个简单的误差模型；这些干扰大概是由诸如镜子和透镜等光学元件引起的。展示了确定误差模型中参数的实验方法。为了验证干涉仪的二维轮廓测量能力，观察了存储在SPring - 8储存环中在不同工作点运行的电子束。在接近微分共振的工作点处，清晰地观察到垂直方向上束斑从20微米展宽到120微米以及束倾斜角的变化。然而，由于上游真空管道的孔径较窄，垂直空间分辨率受到衍射掩膜孔径可用垂直间距的限制。
