Nonconservative charged-particle swarms in ac electric fields.

A time-dependent multi-term technique has been developed and employed to solve the space- and time-dependent Boltzmann equation for charged-particle swarms in ac electric fields. This technique allows for the accurate calculation of both the full set of transport coefficients and the phase-space distribution function. This technique avoids restrictions on the field amplitude and frequency and/or the charged-particle to neutral molecule mass ratio traditionally associated with many contemporary investigations. To our knowledge, it represents the first rigorous treatment of the explicit effects of nonconservative processes on transport coefficients in ac electric fields. The phenomena associated with these explicit effects of nonconservative processes are striking (e.g., negative phase lags in the drift velocity for an attaching gas), and the errors associated with traditional treatments of ionization and attachment on the transport coefficients are highlighted.