Stochastic ion heating by orbit chaotization on electrostatic waves and nonlinear structures

We demonstrate that satellite observations of intense transverse ion energi zation could be explained by stochastic ion heating on short perpendicular wavelength electrostatic waves and structures produced by the decay of disp ersive Alfven waves (DAW) This mechanism is related to the chaotization of ion orbits which leads to strong stochastic heating when the electric field gradient fulfills the inequality partial derivative E-x/partial derivative x > Omega B-0 (here Omega is the ion gyrofrequency and B-0 is the ambient magnetic field). We also show that the energy sourer for this process is pr ovided from dissipation of the Poynting flux of DAW. which appear to form a n energy cascade from large scales lambda(perpendicular to) similar to kilo meters down to lambda(perpendicular to) similar to 50 m where the dissipati on through the ion heating is observed.