Research objectives and content
The objectives of this research is to investigate theoretically the time evolution and stability of ionization waves (IW) that propagate in an external electric field and result in electrical breakdown of gases. The planar IW will be considered within the framework of the system of equations containing the rate equations for electrons and ions taking account of the Townsend mechanism of ionization and the Poisson equation for the self -consistent electric field. For 1D case this system can be reduced to the first-order nonlinear partial differential equation for the electric field, which can be solved analytically for some particular dependencies of the ionization frequency on the local electric field and numerically in the general case. These tools will allow the investigation of the interactions of various IW and the events resulted from the collisions of two IW. For stationary moving planar IW the analysis of their stability will be carried out on the basis of the dispersion equation for the complex eigenfrequencies which will be obtained for the linearized system of partial differential equations describing small 2D perturbations superimposed on nonlinear 1D solutions respresenting stationary moving IW. Both asymptotic and numerical methods will be employed for studying the stability. This analysis is intended for explanation of instabilities of the IW and streamers observed in discharge gaps with planar electrode walls.
Training content (objective, benefit and expected impact)
This scientific visit will extend the knowledge of the scientific group at the Physics Department of the University of Madeira supervised by Prof. Benilov in the field of kinetics of non-equilibrium plasma. physics of gaseous discharge and the general theory of autowaves in active and dissipative systems These fields are close to scientific activities of the group of Prof. Benilov, whose contributions to physics of low-temperature plasma are significant and well-known. This research will provide the basis for new projects that can be suggested for MS and/or Ph.D. students of the Physics Department at Madeira University and for new course on physics of ionization waves for graduate and postgraduate students.