Phase space profile measurement using an X-ray pinhole camera

Transverse beam profiles in the real (x,y) and phase (y,y) spaces were obtained by an X-ray pinhole camera sensitive to synchrotron radiation in the TRISTAN Accumulation Ring (AR). Vertical Twiss parameters and the vertical and horizontal emittances are derived from the profiles. A pinhole cannot see the whole beam vertically because of the small cone angle of the radiation. Two measurements were made to solve this problem. The first measurement was made by moving the pinhole vertically; the second was made by using a multiple pinhole plate. An image on a fluorescent screen is observed by a CCD (charge coupled device) camera, digitized, and stored. The phase space and the real space profiles are then reconstructed. A nonlinear least-squares program fits the resultant profiles to a two-dimensional Gaussian distribution to derive the Twiss parameters and emittances