Trapped-electron stochasticity induced by frequency-modulated waves.

It is shown that for electrons trapped in a static potential a finite-amplitude frequency-modulated wave induces stochastic motions (and diffusion) in electron orbits over a significantly larger area of phase space than a single frequency wave of the same amplitude. The wavelength of the frequency-modulated fields is unimportant if it is greater than twice the width of the static potential. It is proposed that this be used for pumping of mirror trapped electrons to enhance the confining potential in a tandem mirror cell.