Charge stripping of U238 ion beam by helium gas stripper

Abstract

Development of a nondestructive, efficient electric-charge-stripping method is a key requirement for next-generation high-intensity heavy-ion accelerators such as the RIKEN Radioactive-Isotope Beam Factory. A charge stripper employing a low-Z gas is an important candidate applicable to high-intensity uranium beams for replacing carbon-foil strippers. In this study, a high-beam-transmission charge-stripping system employing helium gas for U238 beams injected at 10.8 MeV/u was developed and demonstrated for the first time. The charge-state evolution measured using helium in a thickness range of 0.24-1.83 mg/cm2 is compared with theoretical predictions. Energy attenuation and energy spread due to the helium stripper are also investigated.