|
Journal of Physical Studies 24(1), Article 1401 [9 pages] (2020)
DOI: https://doi.org/10.30970/jps.24.1401 EMITTING CHARACTERISTICS AND PARAMETERS OF GAS-DISCHARGE PLASMA ON A MIXTURE OF MERCURY DICHLORIDE VAPOR WITH NITROGEN
A. O. Malinina
Uzhhorod National University,
|
 |
The article presents the results of the studies of optical characteristics and parameters of a gas-discharge barrier-discharge plasma on a mixture of mercury dichloride vapor with nitrogen, which was the working medium of an exciplex gas-discharge emitter. The purpose of the study was to identify the regularities in the optical characteristics of a gas-discharge plasma on a mixture of mercury dichloride vapor with nitrogen; to determine the partial pressure of a buffer gas nitrogen at which the maximum radiation power in the blue-green spectral range in the emitters is reached; to determine the plasma parameters depending on the value of the reduced electric field ($E/N$ is the ratio of the electric field strength to the total concentration of the components of the working mixture) and also establish their values for the $E/N$ value at which the maximum radiation power was observed in the experiment. The working mixture in the atmospheric-pressure barrier discharge was excited by a power source with a pulse-periodic output voltage with the possibility of frequency tuning in the range of 1-20 kHz and amplitude of voltage pulses within 10-30 kV. Plasma parameters were determined numerically based on the electron energy distribution function (EEDF) in discharge. EEDF was determined by solving the kinetic Boltzmann equation in two-terms approximation using the well-known program ``Bolsig +''. It was found that the double-pulse excitation mode of the working mixture allows for an increase in the radiation power of the source in the blue-green spectral region due to the presence of an additional process of increasing the population of the $B^2Σ^+_{1/2}$-state of mercury monochloride, namely the collision of electrons with mercury monochloride molecules, which are in the ground $X^2Σ^+_{1/2}$-state. The rate constant of the process, which leads to the formation of mercury monochloride molecules, is $2.3 \cdot 10^{-15}$ m${}^{3}$/s for a reduced electric field $E/N = 4.57\cdot10^{-15}$ В $см^2$, at which, under the experimental conditions, the maximum radiation power was observed in the blue-green spectral region ($λ_{\rm max} = 557$ nm).
