Generation and focusing of an intense long pulse proton beam

Summary form only given, as follows. Results of an experimental study aiming at the creation of a long pulse proton beam facility with a pulse duration longer than 10 /spl mu/s and a power density of 10 MW/cm/sup 2/ on the target are presented. The experiments were carried out at the intermediate stage facility PROFA consisting of a vacuum diode as proton beam source and a two stage focusing channel combining ballistic focusing and magnetic compression. In the diode a new type of a large area proton source-a multi spark anode-was employed. This anode produces a surface plasma layer by igniting a discharge along 750 polyethylene units, which are homogeneously placed over the anode surface. As a cathode unit a multipoint explosive emission cathode or a metal grid was used. The diode operation under different conditions and the efficiency of the ion beam transportation and focusing with different methods for space charge neutralization are discussed.