Wire scanner beam size monitor for ATF

A beam size monitor for emittance measurement is required to have around 10 μm resolution for injector linac, and to have a few tenth μm resolution for an extracted beam from a damping ring in Accelerator Test Facility (ATF). A wire scanner is a one of the candidate of a beam size monitor with a high resolution. The design and development study of the wire scanning stage has been done for mainly wire vibration issue. A vibration of wire was studied using small spot size of laser light, and we found that vibration amplitude during off-resonance movement was less than 1 μm. A detection of beam size signal was done by a scintillator gamma detector placed at downstream of the wire stage. The beam test using Tohoku 300 MeV Linac was done and the emittance was measured by this wire scanner. The design and beam test results are described. (author)