Energetic Particle Cross-Field Diffusion: Interaction with Magnetic Decreases (MDs)
B.Tsurutani, G.S. Lakhina, D. Winterhalter, J.K. Arballo, C.Galvan
and R. Sakurai

Jet Propulsion Laboratory, Calif. Inst. Tech., Pasadena, Calif.
Magnetic field decreases (MDs) are detected in the heliospheric polar regions. The properties of the MDs will be described. Charged particle interactions with the MDs lead to particle guiding center displacements and particle cross-field diffusion. We develop analytic expressions for the amount of displacement per interaction and use Monte Carlo type calculations to determine diffusion rates as a function of particle energy. We show an example where the diffusion rate of 1 MeV protons is 0.1 times the Bohm diffusion rate.