Backstreaming Pickup Ions

Abstract Ions that are reflected at the shock front and escape back into upstream region can play role of ions start to be accelerated by a diffusive acceleration mechanism. Backstreaming have been shown generated from superthermal tail solar wind sufficiently high temperatures. The number such was found low they were not angles exceeding 50°. mechanism production is multiple reflection when an ion changes direction motion inside ramp for first time, due cross-shock potential. Since pickup (PUIs) constitute strongly population protons substantially stronger backstreaming PUIs expected. We study in planar stationary using test particle analysis. used model inspired observed profile termination shock. influence magnetic compression, angle, overshoot analyzed. It generation this more efficient than thermal wind. fraction rapidly increases with increase compression decrease angle. Overshoot enhances allows it larger angles. No 60°. results analysis supported full-particle simulations.