We studied low-energy (1.57 keV) electron-spin polarized He-4(+) ion scattering on various 5d transition metal targets. The scattered ion intensity generally differed between the incident He+ ions with up and down spins. This spin dependent ion scattering is attributed to the spin orbit coupling (SOC) that acts transiently on the He+ 1s electron spin in the He+-target binary collision. We observed that the amplitude of the spin dependence in ion scattering, i.e., the spin asymmetry, differs between 5d transition metal targets. This target element dependence of the spin asymmetry is discussed in terms of re-ionization of He-0, which originates from the neutralization of the He+ ion during the He+-target collision. Since the re-ionization is spin independent process, it degrades the effective spin polarization of the He+ ion beam. This explains smaller spin asymmetry with the target on which He-0 is re-ionized with higher rate. (C) 2014 Elsevier B.V. All rights reserved.