LABORATOIRE PLASMA ET CONVERSION D’ENERGIE - UMR5213

PARTICIPANTS

Post-Docs Bhaskar Chaudhury

Students GQ Zhu

Permanent J.P. Boeuf

PARTNERS

This work is performed in the frame of the PLASMAX project of RTRA STAE (collaborative project between ONERA, GREPHE/LAPLACE, GRE/LAPLACE, and IMT) and in collaboration with O. Pascal, GRE/LAPLACE

This movie won the Oscar Buneman award at the 21st International Conference on Numerical Simulation of Plasmas, in Lisbon, October 2009.

BACKGROUND

Depending on pressure and power, microwave breakdown can lead to a variety of transient, filamentary plasma patterns. Recent experiments [1], [2] have clearly shown, using CCD imaging, the formation of filaments oriented in the direction of the electric field of the wave and organized in a pattern moving toward the microwave source. These experiments were performed at or around atmospheric pressure in air and other gases using a high power, high frequency microwave source (focused Gaussian beam from a 1.5 MW 110 GHz gyrotron with 3 ms pulse).

We have developed a model of microwave breakdown under the conditions of Refs. [1], [2] where FDTD solutions of Maxwell equations are coupled with a simple, quasineutral plasma model that can describe charged particle transport due to diffusion, and plasma generation and decay due to ionisation, attachment and recombination. This simple model can reproduce very well most of the observed properties of the plasma pattern formation and evolution.

REFERENCES

[1]Y. Hidaka, E. M. Choi, I. Mastovsky, M. A. Shapiro, J. R. Sirigiri, and R. J. Temkin, “Observation of Large Arrays of Plasma Filaments in Air Breakdown by 1.5-MW 110-GHz Gyrotron Pulses,” Phys. Rev. Lett. 100 035003 (2008).

[2] Y. Hidaka, E. M. Choi, I. Mastovsky, M. A. Shapiro, J. R. Sirigiri, R. J. Temkin, G. F. Edmiston, A. A. Neuber, and Y. Oda, Plasma Structures Observed in Gas Breakdown using a 1.5 MW, 110 GHz pulsed gyrotron, Phys. Plasmas, 16 055702 (2009)