REVERSE SHOCK ACCELERATION OF ELECTRONS AND PROTONS AT MID-HELIOLATITUDES FROM 5.3-3.8-AU

We examine the intensity, anisotropy and energy spectrum of 480-966 ke V protons and 38-315 keV electrons observed by the HI-SCALE instrument on Ulysses associated with Corotating Interaction Regions (CIR) from mid-1992 to early 1994. The particle events are most clearly ordered b y the reverse shocks bounding the CIRs. The bulk of the ion fluxes app ear either straddling, or with their maximum intensity following, the reverse shock. The electron intensities rise sharply to their maximum upon the passage of the reverse shock, and are delayed with respect to the protons. We believe that following acceleration at the reverse sh ock the electrons re-enter the inner heliosphere and mirror, to return to the reverse shock for repeated acceleration. This process is more effective for electrons (v similar to c/2) than for ions, and also fav ours the higher velocity electrons, which accounts for the observed sp ectral hardening with latitude.