Flying wire beam profile monitors at the KEK PS main ring

Abstract

Transverse beam profile monitors called “Flying Wires” have been installed and operated at the 12-GeV main ring of the KEK Proton Synchrotron. A carbon wire of 7μm in diameter scans the beam with a maximum speed of 20m/s and produces secondary particles from the beam–wire scattering. The minimum wire material and fast scanning speed have been chosen to achieve the precise profile measurement and minimum beam destruction because the requirements are critical for the lowest kinetic energy of 500MeV. The basic performance has been thoroughly tested. A new stroboscopic procedure has been established to reconstruct beam profiles that rapidly change with a time scale of 1ms or less. The monitors have demonstrated capability of obtaining profitable information for the mechanism of the halo formation and beam loss.