Development of non-invasive electron beam position monitor based on coherent diffraction radiation from a slit

Diffraction radiation is emitted when a charged particle passes through in the vicinity of a boundary between two media with different dielectric constants. An aperture, a slit, and an edge are used for diffraction radiation target. It is theoretically suggested that an asymmetry of a spatial distribution of diffraction radiation appears by changing the beam trajectory with respect to the center of a rectangular slit. We have developed the beam position monitor using the coherent diffraction radiation generated when a sub-picosecond electron beam passes through the rectangular slit. A theoretical background of the diffraction radiation emitted from the slit and experimental results will be reported.