Low Energy Energetic Particle’s Streaming as Measured by Ulysses EPAC Experiment from 1991–2000

The KEP/EPAC instrument, on board Ulysses spacecraft, measures directional intensities of interplanetary energetic protons and ions. We analyze Compton‐Getting corrected data received from the beginning of the year 1991 to the end of 2000 and we also perform statistical analysis for the observed angle between first‐order anisotropy of particle distribution and interplanetary magnetic field. The results show that the energetic particle’s anisotropy is mostly in the direction perpendicular to the magnetic field, indicating a diffusion across the magnetic field lines. A strong correlation is found between the perpendicular to the magnetic field streaming of protons and ions, in the energy range of MeV, and the solar wind velocity. This correlation is simply interpreted in terms cross‐field particle diffussion in the presence of an ambient plasma density gradient.