Influence of Reflected Ions on the Magnetic Structure of a Collisionless Shock Front

Abstract
A special probe has been used to detect ions reflected from a collisionless shock wave propagating perpendicular to the field in a magnetized, low-β plasma. Reflected ions are observed only above a critical Alfvén number MA2.7, and their orbits coincide with the familiar "foot" on the magnetic structure of supercritical shocks. We discuss the origin of the reflected ions.