Virtual charge state separator as an advanced tool coupling measurements and simulations

Abstract

A new low energy beam transport for a multicharge uranium beam will be built at the GSI High Current Injector (HSI). All uranium charge states coming from the new ion source will be injected into GSI heavy ion high current HSI Radio Frequency Quadrupole (RFQ), but only the design ions U^{4+} will be accelerated to the final RFQ energy. A detailed knowledge about injected beam current and emittance for pure design U^{4+} ions is necessary for a proper beam line design commissioning and operation, while measurements are possible only for a full beam including all charge states. Detailed measurements of the beam current and emittance are performed behind the first quadrupole triplet of the beam line. A dedicated algorithm, based on a combination of measurements and the results of advanced beam dynamics simulations, provides for an extraction of beam current and emittance values for only the U^{4+} component of the beam. The proposed methods and obtained results are presented.