  The vector analyzing power has been measured for the elastic scattering of
neutron-rich 6He from polarized protons at 71 MeV/nucleon making use of a newly
constructed solid polarized proton target operated in a low magnetic field and
at high temperature. Two approaches based on local one-body potentials were
applied to investigate the spin-orbit interaction between a proton and a 6He
nucleus. An optical model analysis revealed that the spin-orbit potential for
6He is characterized by a shallow and long-ranged shape compared with the
global systematics of stable nuclei. A semimicroscopic analysis with a
alpha+n+n cluster folding model suggests that the interaction between a proton
and the alpha core is essentially important in describing the p+6He elastic
scattering. The data are also compared with fully microscopic analyses using
non-local optical potentials based on nucleon-nucleon g-matrices.
