“…The main contribution to the Coulomb losses of protons of the radiation belts make the cold plasma electrons (Tverskoy, 1964(Tverskoy, , 1965(Tverskoy, , 1968(Tverskoy, , 1969Nakada and Mead, 1965;Schulz and Lanzerotti, 1974;Spjeldvik, 1977, Jentsch, 1984, the density of which, N e , is strongly dependent on L (see Fig. 5).…”