Residence lifetimes of 1.79‐ to 2.15‐MeV protons in the equatorial region of the Jovian magnetosphere

The magnitude of the strong flow of 1.79–2.15 MeV protons away from the Jovian magnetic equator is used to estimate the residence lifetimes of these protons in the equatorial source region. The lifetime is approximately 1.2 × 105/(R − 5.8)² s, where R is distance in Jovian radii from Jupiter's center to the equatorial region of interest. At Europa and Ganymede (but not at Io) this lifetime is 1–2 orders of magnitude shorter than sweepup lifetimes by the moons. The fluxes of these protons, integrated over the observed range from 6 to 40 Jovian radii, amount to 3 × 1023 particles per second, per degree of longitude and carry away about 9 × 1017 ergs per second per degree.