Charge state distribution of Kr 86 in hydrogen and helium gas charge strippers at 2.7 MeV / nucleon

The charge state distributions of krypton (Kr-86) with an energy of 2.7 MeV/nucleon were measured using hydrogen (H-2) and helium (He) gas charge strippers. A differential pumping system was constructed to confine H-2 and He gases to a thickness sufficient for the charge state distributions to attain equilibrium. The mean charge states of Kr-86 in H-2 and He gases attained equilibrium at 25.1 and 23.2, respectively, whereas the mean charge state in N-2 gas at equilibrium was estimated to be less than 20. The charge distributions are successfully reproduced by the cross sections of ionization and electron capture processes optimized by a fitting procedure.