Observations of low energy oxygen at voyagers 1 & 2 Original Research Article

We discuss recent progress toward identifying and understanding low-energy, heavy-ion measurements from the Low Energy Charged Particle (LECP) instruments on the heliospheric probes Voyagers 1 and 2. These heavy-ion signatures, which we interpret as pickup oxygen ions, appear as excess counts in the sunward viewing sectors (22.5° half-angle) of three, single-parameter ion channels that respond to protons ∼30–140 keV and oxygen ions ∼4–14 keV/nuc. We have previously discussed Voyager 1 data during the solar inactive period 1995 to 1998. New data discussed herein include those from Voyager 1 during 1985–1988, also a period of low solar activity, and from Voyager 2 during 1995 to 1998.