Initial measurements of O-ion and He-ion decay rates observed from the Van Allen probes RBSPICE instrument

H-ion (approximate to 45 keV to approximate to 600keV), He-ion (approximate to 65 keV to approximate to 520 keV), and O-ion (approximate to 140 keV to approximate to 1130keV) integral flux measurements, from the Radiation Belt Storm Probe Ion Composition Experiment (RBSPICE) instrument aboard the Van Allan Probes spacecraft B, are reported. These abundance data form a cohesive picture of ring current ions during the first 9 months of measurements. Furthermore, the data presented herein are used to show injection characteristics via the He-ion/H-ion abundance ratio and the O-ion/H-ion abundance ratio. Of unique interest to ring current dynamics are the spatial-temporal decay characteristics of the two injected populations. We observe that He-ions decay more quickly at lower L shells, on the order of approximate to 0.8 day at L shells of 3-4, and decay more slowly with higher L shell, on the order of approximate to 1.7 days at L shells of 5-6. Conversely, O-ions decay very rapidly (approximate to 1.5 h) across all L shells. The He-ion decay time are consistent with previously measured and calculated lifetimes associated with charge exchange. The O-ion decay time is much faster than predicted and is attributed to the inclusion of higher-energy (> 500 keV) O-ions in our decay rate estimation. We note that these measurements demonstrate a compelling need for calculation of high-energy O-ion loss rates, which have not been adequately studied in the literature to date.