A. A. Deryugin

A numerical simulation of Trichel-pulse formation in a negative corona

A new quasi-one-dimensional model for a negative corona in air is formulated allowing for the quantitative description of the mechanism of Trichel-pulse formation. Detailed analysis of the processes controlling pulse dynamics is made. Comparison with experiment for a short-gap corona demonstrates a reasonable agreement with the shape of the pulse and in the average characteristics of the negative corona.

Discharge production of the singlet delta oxygen for an iodine laser

The properties and kinetics of singlet delta oxygen (SDO) metastables in discharge plasma, which are important for the development of the discharge excited oxygen-iodine laser, are discussed. A short description is given of available experimental activity in the development of SDO generators. Specific requirements to the SDO discharge generator are reported. The capability of different kinds of discharge to meet these requirements is evaluated. Issues are discussed which are important for the study of SDO kinetics in more detail, including processes involving individual electronic-vibrational states.

Self-oscillations of a positive corona in nitrogen

The oscillatory behaviour of a glow positive corona in pure nitrogen is observed experimentally. The regular self-oscillations of the corona current and the light emission from the glow ionization region, as well as the averaged volt-ampere characteristics of this discharge, are studied comprehensively within gas pressure range 10-765 Torr. It is revealed that the positive glow corona generates a soft x-radiation. This radiation plays a crucial role in the photo-ionization of nitrogen. Furthermore, it provides a fast positive feedback for electron avalanches through the ionization region of the corona. The results of numerical modelling of the glow corona under free-running oscillations are also presented.

DC Glow Discharge with Fast Gas Flow for Flue Gas Processing

The problem of environmental pollution has a growing importance and is today of global value for the world. Acid rain, greenhouse effect, and ozone depletion are well known manifestations of the atmospheric contamination by SO2, NOx, CO2 and chlorofluorocarbons. The non-thermal plasma techniques developed recently provide an effective means for pollution control. Of these the most elaborate one is the electron-beam irradiation of flue gases. Pilot-plant tests for the e-beam technique have been done in Japan (Kawamura et al. 1984), Germany (Jordan 1990), Poland (Chmielewski et al. 1992) and the USA (Frank et al. 1990). Promising results have been shown also by the pulse corona for the simultaneous removal of NOx and SO2. Industrial-scale experiments have been performed at the coal-burning power station in Marghera near Venice in Italy (Dinelli et al. 1990). First results on application of silent discharge to the conversion of SO2 to SO3 have been recently reported (Dhali et al. 1991).

Multidimensional modeling of excimer laser

The full-detailed kinetic model of XeCl laser is developed, which includes self-consistent solution of the electron Boltzmann equation, taking into account the electron collisions both with other and with vibrationally and electronically excited particles as well as the system of equations of plasma chemical kinetics and radiation transfer. 1-D, 2-D and 3-D models are worked out by simplifying the full kinetic model. The approximate kinetics have been verified to agree well with the detailed kinetics for the conditions investigated. These models have been applied to describe the effects of nonuniform pumping and spatial distribution of plasma components on the laser characteristics. The 1-D model of the electric discharge-pumped excimer laser will be presented and the results of 3-D mathematical simulation of the e-beam pumped amplifier with a large aperture will be reported. This model includes 2-D Monte- Carlo simulation of the fast electron transport and 3-D calculation of the amplified spontaneous radiation transfer. The amplified beam intensity distribution is calculated and the optical quality of the output beam is estimated, taking into account the refraction index variation across the amplifier aperture. A fast procedure to find out the laser resonator parameters for the maximal efficiency will be proposed, including the effects of spatial nonuniformity of the active medium.