Plasmoid formation and expansion in a microwave field
- Univ. of Colorado, Boulder, CO (United States)
At low altitudes, the concentration of free electrons in the atmosphere is small and a microwave pulse above the theoretical breakdown limit can lead to the formation of micro-plasmas localized around each seed electron and whose spatial dimensions grow quickly during the pulse. At higher altitudes, the free electron density and electron diffusion increase so that breakdown becomes much more diffuse and is well described by classical theory. In a first part of this paper, the authors present results from a 2D fluid model of the formation and extension of a localized plasma (plasmoid) at low altitudes, under a microwave pulse, for conditions where the pulse duration is longer than the breakdown time. The model is valid for plasma dimensions less than the wave length and the skin depth. The plasma is supposed to be quasi-neutral and the electron continuity equation is solved together with the current equation. Results show that once the density of the avalanche reaches a critical density, the plasma continues to grow and extends mainly in the directions parallel to the electric field. In a second part the authors discuss microwave breakdown at higher altitudes, by comparing the predictions of simple breakdown criteria to those of more accurate descriptions of microwave propagation involving coupled solutions of Maxwell equations and electron transport equations.
- OSTI ID:
- 51805
- Report Number(s):
- CONF-940604--; ISBN 0-7803-2006-9
- Country of Publication:
- United States
- Language:
- English
Similar Records
Sparse Breakdown and Statistical "Sneakthrough" Effects in Low-Altitude Microwave Propagation
Single and repetitive short-pulse high-power microwave window breakdown