DIFFERENCES BETWEEN THE 0.35-1.0 MEV NUCLEON H/HE RATIO IN SOLAR AND CO-ROTATING EVENTS AT HIGH HELIOLATITUDE/

We discuss measurements from the Ulysses spacecraft of the 0.35 - 1.0 MeV/nucleon H/He intensity ratio at high heliolatitudes. In early 1994 two transient solar events were detected in the gaps between particle intensity increases associated with the passage at low latitude of a co-rotating interaction region. The H/He ratio was greater than or sim ilar to one order-of-magnitude lower in the co-rotating events than in the transient solar events. Several similar instances, but not so cle anly separated, were observed from mid-1992 to the end of 1993. We int erpret the lower H/He ratio in recurrent events as the result of effic ient acceleration of interstellar pickup He+ at corotating reverse sho cks to which Ulysses remains connected even at high heliolatitudes.