It has recently been shown that it is possible to quantitatively model the entry of magnetosheath ions and their access to the dayside ionosphere with surprisingly good results. In the same model, electrons had access to the region poleward of the cusp at unrealistically high intensities. We improve the previous model by imposing the constraints of charge quasineutrality and introducing more realistic electron magnetosheath populations. It turns out that no potential drop within the cusp proper is either needed or observed in order to enforce charge neutrality, since ions, as well as electrons, can enter freely, and they originally have the same density in the magnetosheath. Poleward of the magnetic cusp, ion entry is sharply curtailed because of the tailward magnetosheath flow, and the potential required and observed rises rapidly. This potential eliminates access of the ''core'' population of the magnetosheath electrons to the ionosphere. The typical polar rain signature observed at low altitudes fits best with the suprathermal solar wind electron population (either halo or both halo and strahl components). The model clearly shows that ions previously identified at low altitude as ''mantle'' do indeed cross the magnetopause tailward of the magnetic cusp, that is, the ionospheric mantle signature consists of ions originating in the high-altitude mantle. A single ion spectrum within the low-altitude cusp proves to consist of magnetosheath ions which have crossed the frontside magnetopause from a range of positions which commences with the merging site and extends to the magnetic cusp, but which is typically only 1--3 RE wide along the direction of the field line convection. ¿ American Geophysical Union 1996