Ion acceleration through an auroral potential structure: Numerical simulations

We perform numerical simulations for the acceleration of O + ions in a potential well which has an exponential form in x-direction with a characteristic length Lx. The oxygen ions are moving in the presence of constant magnetic field Bz and a constant electric field Ey. We trace the orbits of individual particles for different initial conditions (phase angle and kinetic energy). We found that depending upon the initial conditions ions can be either accelerated or decelerated. Furthermore we perform a parametric study for the interactions of monoenergetic and Maxwellian type of ion distributions, using random phase angle injection of the particles, with respect to our model parameter- the characteristic length of the potential (Lx).