Distribution of the Earth's radiation belts protons over the drift frequency of particles

Abstract. On the base of generalized data on the proton fluxes of the Earth's radiation belts (ERB) with energy from E ~ 0.2 MeV to 100 MeV at drift shells L from ~ 1 to 8, constructed stationary distributions of the ERB protons over the drift frequency fd of protons around the Earth. For this, direct measurements of proton fluxes of the ERB in the period 1961–2017 near the plane of the geomagnetic equator were used. The main physical processes in the ERB manifested more clearly in these distributions, and for protons with fd > 0.5 mHz at L > 3 distributions of the ERB protons in the space {fd, L} have a more orderly form than in the space {E, L}. It has been found also that the quantity of the ERB protons with fd ~ 1–10 mHz at L ~ 2 does not decrease, as for protons with E > 10–20 MeV (with fd > 10 mHz), but increases with an increase in solar activity. This means that the balance of radial transport and losses of the ERB low-energy protons at L ~ 2 is disrupt in advantage of transport: for these protons, the effect of an increase in the radial diffusion rates with increasing in solar activity overpowers the effect of an increase in the density of the dissipative medium.