Diagnostic of the compensation process of ion beams with a time-resolving ion energy spectrometer

Space-charge compensated high-perveance ion beams are of main interest for the injection into RFQ systems. Space-charge compensation enhances the maximum transportable current in low energy beam transport lines which is mainly limited by space-charge forces. The compensation electrons are usually produced by residual gas ionisation. In this case beam pulses reach the final degree of compensation after a certain time. To investigate the compensation processes of a periodically decompensated beam, a time-resolving residual gas ion energy spectrometer was developed. Results of measurements and corresponding numerical simulations will be presented