Three years of Imp 5 data show that the magnetopause layer of energetic electrons was present during 227 of 230 orbits over this period and extends along the magnetopause from geomagnetic latitudes as low as 40¿ to latitudes corresponding to the polar cap. It also exists at the boundary between the magnetosheath and the polar cusp region. The data show that the integral energy spectrum of these electrons (Ee>18 keV) varies greatly with the planetary Kp index and hardens with increasing Kp values. The average spectrum can be represented by a power law J (>E) ∝E-&agr;, where &agr;=1.94¿0.19. The intensity of the magnetopause layer electrons increases with increasing Kp values and also has a weak dependence on the magnitude of the north-south component of the interplanetary magnetic field. The energy density of the energetic electrons in this layer is of the order of 10-14 erg/cm3. |