A NOVEL BEAM-PROFILE MONITOR FOR STORAGE-RINGS

We have developed a novel, nondestructive, beam-profile monitor for io n storage rings. The horizontal profile of the stored ion beam is dete rmined by detecting electrons from the ionization of the residual gas with a two-dimensional position sensitive detector. The strong magneti c field, provided by one of the bending magnets, conserves the informa tion on the initial horizontal positions of ionized electrons during t heir transport to the detector by means of a vertical electric field. The monitor is tested at the storage ring CRYRING in Stockholm for a 6 MeV/amu D+ beam. We show that in this case, where the lifetime of the stored beam is restricted by single scattering on the residual gas, a reduction of the lifetime occurs due to the reduced angular acceptanc e.