Two-dimensional synchrotron radiation interferometer for electron beam profile diagnostics

Two-dimensional synchrotron radiation interferometer for non-destructive diagnostics of transverse electron beam profile is explained. The interferometer developed at the SPring-8 enables simultaneous measurement of beam sizes along the major and minor axes and beam-tilt angle of an assumed elliptical Gaussian distribution. A point-spread function of the interferometer will be distorted by wavefront error presumably generated from optical elements, such as mirrors and lenses. An experimental method to calibrate the point-spread function is described. The two-dimensional profiling capability of the interferometer was verified by observing the behavior which the beam axis rotates as the working point approaches the linear coupling resonance condition of the betatron tunes. In relation to Top-up operation started at the SPring-8 from May 2004, oscillation of the stored beam induced by the injection was measured as the variation of the effective beam profiles. This topic is also introduced. (author)