How do Cosmic Rays enter and leave the Heliosphere?

Abstract

The surprisingly abrupt increase of GCRs at the heliopause (HP) seen by both Voyager spacecraft poses a challenge to conventional diffusion models and raises the question how do galactic and anomalous cosmic rays (GCRs and ACRs) enter or leave the heliosphere. In this speculative work we address the possibility that heliospheric currents sheets (HCSs) can provide channels of fat transport to and from the HP. By virtue of fast particle drifts along the HCS, cosmic rays find an easier access to and from the heliosphere at places where a HCS reaches the HP. Numerical simulations using simple toy models will be presented and discussed at the Conference. The possible dynamical role of these cracks will be also considered. We suggest that this mechanism could be responsible, in part, for the apparent imbalance between the total pressures inside and outside the HP, and could perhaps contribute to the flatter than expected size of the inner heliosheath between the termination shock(TS) and HP.