**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.