Anomalous Cosmic Rays outside of the Termination Shock

Abstract : Anomalous Cosmic Rays (ACR) are most probably generated at the solar wind termi- nation shock. When observed in the region inside the shock, the ACR energy spectrum is significantly modulated. The region outside the shock is so far inaccessible to obser- vations. However, the low energy (~ 100 keV) part of the spectrum beyond the shock could be sampled by means of energetic neutral atoms (ENA), into which the ACR ions convert by charge-exchange with the neutral atoms. As the distribution of ACR reflects the large-scale structure of the heliosphere, this offers a possibility of imaging the outer heliosphere by ENA from this source.