LONGITUDINAL BEAM EMITTANCE MONITOR FOR 433 MHZ PROTON LINAC

We have developed a longitudinal emittance monitor for a 7 MeV proton beam provided by the 433 MHz Linac at the Institute for Chemical Resea rch, Kyoto University. In the present system, the beam first hits a th in gold target on the beam line, and a fraction of the scattered proto ns comes into a small cavity. After deflected by a rf electric field i n the cavity, the protons finally reach a position sensitive detector (PSD). The PSD gives the information of the energy and position of the individual scattered proton, which enables us to reconstruct the long itudinal distribution of the beam before colliding with the target. Th e phase and energy resolution of the system are estimated to be 13 deg rees and 23 keV full width at half-maximum, respectively. The longitud inal rms emittance measured was 0.39+/-0.07 pi deg MeV under the nomin al operating condition of th: linac. (C) 1996 American Institute of Ph ysics.