Ion Dynamics in Multiple Electrostatic Waves in a Magnetized Plasma

A general theoretical study of the dynamics of ions interacting with multiple elec-trostatic waves, propagating perpendicularly to a uniform magnetic field, is performed. For appropriately chosen frequencies and wavenumbers we discover a new nonlinear phenomenon of coherent acceleration (or deceleration) which energizes (or extracts energy from) ions. Ions whose initial energies are below the lower bound of the chaotic part of phase space can be energized by the nonlinear, coherent phenomenon. We also show that the maximum energy the ions can reach is much higher in the case of several waves than in the case of one wave. The mechanism by which the ions reach these high energies is also mostly coherent.