MEAN FREE PATHS OF ENERGETIC CHARGED-PARTICLES PARALLEL AND ANTIPARALLEL TO THE INTERPLANETARY MAGNETIC-FIELD

A new method to calculate the mean free paths of energetic particles p ropagating parallel and anti-parallel to the interplanetary magnetic f ield, based on quasi-linear theory and the complex spectral polarizati on analysis of the field, is developed and presented. Applications of the method using HEOS 2 (1 AU), Pioneer 10 (5 AU), Pioneer 11 (20 AU), ICE (Giacobini-Zinner's comet) data have been made, showing that: (a) The mean free paths parallel and anti-parallel to the field can be co mpletely different in various regions of the interplanetary medium and different time periods (b) Particles are preferentially scattered in one direction. (c) The parallel and anti-parallel mean free paths beco me equal at certain energy. Comparisons with the results from another computational method are made.