Neon‐20, oxygen‐16, and helium‐4 densities, temperatures, and suprathermal tails in the solar wind determined with WIND/MASS

Abstract

Measurements from the MASS instrument on the WIND spacecraft from late Dec. 94 through Aug. 95 are reported for 20 Ne, 16 O, and 4 He. The average 4 He/ 20 Ne density ratio is 566±87 with considerable variability. The average 16 O/ 20 Ne density ratio is 8.0±0.6 and is independent, within experimental uncertainty, of solar wind speed. The 20 Ne/ 4 He and 16 O/ 4 He temperature ratios at the lowest solar wind speeds are consistent with unity, increasing with increasing speed to values exceeding that expected from mass proportionality. 20 Ne, 16 O, and 4 He distribution functions exhibit high energy tails which are well‐fit by a kappa function.