Investigation of space-charge compensation with residual-gas-ion energy analyser

Low energy beam transport of high perveance beams with magnetic quadrupole focusing requires a high degree of space-charge compensation. Furthermore the build-up time of space-charge compensation has to be short compared to the beam-pulse duration; In order to study the space-charge compensation in the drift sections between the focusing elements of the existing GSI UNILAC injector, the energy spectrum of the residual gas ions produced by the beam and accelerated radially by the space-charge potential can be measured. Hereto a compact electrostatic energy analyser of the Hughes-Rojansky type [1] has been built allowing for time integrated as well as time resolved measurements. First measurements in time integrating mode have been performed.