KINETIC TEMPERATURE RATIOS OF O6- OBSERVATIONS FROM WIND( AND HE2+ )MASS AND ULYSSES/SWICS/

We present results from a two spacecraft study of the ratio of O6+ and He2+ kinetic temperatures as a function of solar wind speed. Data fro m the Wind/MASS and Ulysses/SWICS instruments both indicate the O6+/He 2+ kinetic temperature ratio increases with increasing solar wind spee d, peaking near 500 km/s. Above 500 km/s, the ratio appears to decreas e slightly. Values near unity were obtained for slow solar wind while fast wind yielded ratios substantially higher than what is expected fr om the general rule T-i/T-j approximate to M(i)/M(j). (1) Although ave raging over all data would result in the nominal ratio of 4, deviation s from equation (1) appear to be common and the assumption of equal th ermal velocities should not be made a priori.