Nonadiabatic Ponderomotive Barriers*

A ponderomotive potential is an effective potential seen by a particle in ac field in average over the fast oscillations. It is not a true potential though, and, if the ac field is in resonance with particle natural oscillations, the particle can exhibit irreversible drift motion [1-3]. A new ponderomotive potential is found for this case that can capture nonadiabatic dynamics [4]. The particle drift in this new potential resembles the motion of a quantum object in a conservative field [5]. Among other applications, these nonadiabatic potentials can perform selective separation and cooling of plasma species or drive electric current by asymmetrically transmitting thermal particles in a preferential direction [1, 2, 6].\newline [1] N.J. Fisch, J.M. Rax, and I.Y. Dodin, Phys. Rev. Lett. {\bf 91}, 205004 (2003).\newline [2] I.Y. Dodin, N.J. Fisch, and J.M. Rax, Phys. Plasmas {\bf 11}, 5046 (2004).\newline [3] I.Y. Dodin and N.J. Fisch, J. Plasma Phys. {\bf 71}, 289 (2005).\newline [4] I.Y. Dodin and N.J. Fisch, Phys. Lett. A {\bf 349}, 356 (2006).\newline [5] I.Y. Dodin and N.J. Fisch, Phys. Rev. Lett. {\bf 95}, 115001 (2005).\newline [6] I.Y. Dodin and N.J. Fisch, Phys. Rev. E {\bf 72}, 046602 (2005).