James Drake
University of Maryland
Is the magnetic field in the outer heliosphere laminar I:reconnection dynamics, particle acceleration and post-reconnection bubbles
The recent observations of the anomalous cosmic ray (ACR) energy spectrum as Voyagers 1 and 2 crossed the heliospheric termination shock have called into question the conventional shock source of these energetic particles. We have suggested that the sectored heliospheric magnetic field, which results from the flapping of the heliospheric current sheet, reconnects in the heliosheath.Particle-in-cell simulations reveal that most of the magnetic energy goes into the interstellar pickup ions with significant but smaller amounts of energy going into electrons and heated solar wind ions. The predicted spectra of ACRs based on this model is consistent with the Voyager observations. An important question is how to determine from the Voyager data whether the sectored magnetic field has reconnected. The question is not as simple as you might expect because the post-reconnection state of the sectored field region consistes of nested magnetic islands with a periodicity that is similar but more irregular than the unreconnected sectored field. The reconnection dynamics of the sectored field and associated particle acceleration will be discussed with an emphasis on the unusual properties of the post-reconnection nested magnetic islands and associated flows.