Enhanced low energy (1 MeV) ion fluxes in the outer heliosphere.

The Low Energy Charged Particle (LECP) experiment on the Voyager 2 spacecraft in the outer heliosphere (>10 AU) has observed several occasions when there is a peak in the interplanetary ion spectra for ions of energies ~0.5-1.0 MeV. Such enhancements can last for several days, suggesting that at these times particles of these energies dominate the low energy cosmic population in this region of the heliosphere. Two specific cases are discussed. The enhancements seem to be associated with the passage of transient interplanetary shock events, with the ion anisotropies generally showing outflow.