Regular and stochastic orbits of ions in a highly prolate field-reversed configuration

The dynamics of single ions in field-reversed configuration (FRC) is discussed where ions have positive canonical angular momentum. The equations of motion are of two degree-of-freedom system with spatial variables due to angular invariance. The conserved invariant breaks down during crossing of phase-space separatrix which is due to separation of time scales of motion caused by large elongation. An approximate one-dimensional effective potential is also obtained by averaging over fast radial motion for integrable motion in which adiabatic invariant is conserved.