Panagiotis Marhavilas

DISTINCT SHOCK ACCELERATION PROCESSES - EVALUATION OF THE MAGNETIC TRAP DIMENSIONS FORMED UPSTREAM OF AN INTERPLANETARY SHOCK USING MEASUREMENTS OF ULYSSES S/C


ABSTRACT

We analyze the acceleration signatures of energetic ions (E>50 keV) and electrons (E>30 keV) being observed on day 256 of the year 1992 UT, in the vicinity of the surface of a fast-mode quasi-perpendicular interplanetary hydromagnetic shock, using fine time resolution measurements by the HI-SCALE instrument onboard the Ulysses spacecraft (s/c). The observations present strong evidence for the acceleration of energetic particles trapped within magnetic structures on the surface of the fast-mode shock. We discuss the flux-times profiles and particle distributions near the shock in the context of previous theoretical studies and models. Moreover we are in the procedure of evaluating the width L and amplitude A of the magnetic structure by using HI-SCALE measurements and a sinusoidal form geometry.