Measurement of Cross Section of a High-Energy Electron Beam by Means of the X-Ray Portion of the Synchrotron Radiation

Synchrotron light is routinely used in measuring the cross-section of a high-energy, orbiting, electron beam. The resolution of the height measurement is limited by the small vertical opening angle of this light. Because the angle decreases as a fractional power of decreasing wavelength, it is advantgeous to use a shorter wavelength portion of the synchrotron radiation, i.e., the x-ray portion. Accurate measurement of beam height is especially important to the CEA colliding beam program. A pinhole was installed in one of the tangential beam runs and the x-radiation image of the crosssection was recorded with a Polaroid x-ray cassette. A resolution of about 0.1 mm in beam height was obtained. The measured height of the stored beam was in agreement with expectation.