Super-Adiabatic and Sub-Adiabatic Electron Heating Through a Quasiperpendicular Supercritical Shock

Recent statistical analysis of results issued from test particles simulations has been performed in order to analyze quantitatively the adiabaticity violation for electrons traversing a planar quasi-perpendicular shock wave The shock wave is moving in a supercritical regime and its profile is defined by all electric and magnetic field components issued from a full particle simulation. Test particles are initially distributed over a small sphere in 3D velocity space. The main results are: (i) both adiabatic and nonadiabatic electrons are identified and their respective contributions to the total heating are also estimated versus their initial distributions in velocity phases (for a given thermal velocity) and versus the initial thermal velocity. This allows us to determine which part of the distribution function is responsible for nonadiabaticity. (ii) Two distinct nonadiabatic electron populations have been clearly identified: one is super-adiabatic (overheating), the other is sub-adiabatic (overcooling). Results are compared with recent theoretical calculations suggested to explain the existence of these two populations and to identify the underlying mechanisms responsible for their formation. Present results may be of importance for analysing new experimental data issued from CLUSTER-II mission.