• A.H. Lumpkin, W. Berg, N. Sereno, B.X. Yang, C. Yao
  ANL, Argonne, Illinois
• D.W. Rule
  NSWC, West Bethesda, Maryland

Funding: Work supported by U.S. Department of Energy, Office of Basic Energy Sciences, under Contract No. W-31-109-ENG-38.

The challenge of providing nonintercepting beam diagnostics that address transverse parameters such as beam size and divergence in a linear transport line has been met. We have successfully used near-field imaging of optical diffraction radiation (ODR) from a 7-GeV electron beam passing near a single edge of a conducting screen to obtain beam size for the first time [1]. In this case appreciable visible wavelength ODR is emitted for impact parameters of 1 to 2 mm, values that are close to gamma times the reduced observation wavelength. We have now upgraded our imaging system to include an intensified camera; selectable bandpass filters, neutral density filters, and polarizers; a steering mirror; and an optical lens setup that provides either near-field or far-field imaging. The ODR has been obtained in both the single-edge mode and aperture mode with a single pulse of 3.3 nC. Beam-size resolution in the 20-50 micron regime is projected while beam position resolution to 10 microns with a smaller beam and higher optical magnification should be feasible with near-field imaging. Applications to high-energy accelerators that drive x-ray FELs or energy recovering linacs for light sources should be possible.

[1] A.H. Lumpkin et al., "First Near-Field Imaging of Optical Diffraction Radiation Generated by a 7-GeV Electron Beam,” submitted to Phys. Rev. Lett., May 4, 2005.