VOYAGER OBSERVATIONS OF O(-WIND(6) AND OTHER MINOR IONS IN THE SOLAR)

The plasma science (PLS) experiments on the Voyager 1 and 2 spacecraft began making measurements of the solar wind shortly after the two lau nches in the fall of 1977. In reviewing the data obtained prior to the Jupiter encounters in 1979, we have found that the large dynamic rang e of the PLS instrument generally allows a clean separation of signatu res of minor ions (about 2.5% of the time) during a single instrument scan in energy per charge. The minor ions, most notably O+6, well sepa rated from the protons and alpha particles during times when the solar wind Mach number (ratio of streaming speed to thermal speed) is great er than similar to 15. During the Earth to Jupiter cruise we find that that the average ratio of alpha particle number density to that of ox ygen is 66+/-7 (Voyager 1) and 71+/-17 (Voyager 2). These values are c onsistent with the value 75+/-20 inferred from the Ion Composition Ins trument on ISEE 3 during the period spanning 1978 and 1982. We have in ferred an average coronal temperature of (1.7+/-0.1)x10(6) K based on the ratio of O+7 to O+6 number densities. Our observations cover a per iod of increasing solar activity. During this time we have found that the alpha particle to proton number density ratio is increasing with t he solar cycle, the oxygen to proton ratio increases, and the alpha pa rticle to oxygen ratio remains relatively constant in time.