The dynamics of plasma and neutral gas in pressure balance are solved self-consistently to reveal the impact of neutral depletion. Analytical relations that determine the electron temperature, the rate of ionization, and the plasma density are derived. Because of the inherent coupling of ionization and transport, an increase of the energy invested in ionization can nonlinearly enhance the transport process. We show that such an enhancement of the plasma transport due to neutral depletion can result in an unexpected decrease of the plasma density when power is increased, despite the increase of the flux of generated plasma.

• Received 22 April 2005

DOI:https://doi.org/10.1103/PhysRevLett.95.115002