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1.
The subject of investigation is the emission properties of a pulsed-periodic barrier discharge initiated by submicrosecond
pulses (f = 40–1000 Hz) in He-I2 and Ar-I2 mixtures. The investigation is carried out in the spectral range 200–400 nm at a pressure of the working medium of 1–100
kPa and an iodine partial pressure of 130–200 Pa. The dependence of UV emission from the plasma of the barrier discharge at
the 342 nm I2(D′ → A′) band and the iodine atom spectral line at 206.2 nm on the argon and helium partial pressures, excitation pulses
repetition rate, and charging voltage of the capacitor of a short high-voltage pulse modulator is optimized. The contribution
of the 206.2 nm I* spectral line to the UV emission of the barrier discharge is estimated. 相似文献
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The efficiencies of excitation of different atomic and molecular levels of a gaseous medium by a low-current high-frequency
capacitive discharge (HFCD) and a dc discharge are compared theoretically. It is shown that for transitions between lower
vibrational levels of molecules an increase in spectral line intensity by a factor of 1.2–1.6 is observed, and for neon transitions
from high-lying levels, by a factor of 1.5–3.0. The stability of low-current HFCD is experimentally investigated for different
configurations of gas-discharge gaps. The results of these investigations are used in developing compact planar and coaxial
HFCD lasers.
B. I. Spepanov Institute of Physics, Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220071. Translated from Zhurnal
Prikladnoi Spektroskopii, Vol. 64, No. 3, pp. 291–296, May–June, 1997. 相似文献
4.
The spectral characteristics of the emission in the 140-315 nm range from pulsed-periodic capacitive discharges in mixtures
of water vapor and helium and argon are described. In the VUV the most intense bands have maxima at λ = 156.0, 180.3, and
186.0 nm, and in the region of 300–315 nm, at λ = 312.1 and 313.4 nm. The brightness of the emission from the capacitive discharge
plasma is optimized with respect to the partial pressures of helium, argon, and water vapor. The electron kinetic coefficients
of discharges in argon and water vapor mixtures are calculated for E/N = 1–1000 Td. 相似文献
5.
A. K. Shuaibov I. A. Grabovaya Z. T. Gomoki A. G. Kalyuzhnaya A. I. Shchedrin 《Technical Physics》2009,54(12):1819-1824
The output characteristics and parameters of the plasma of a powerful gas-discharge source of UV radiation are studied. The
UV source uses He-I2 and Xe-I2 mixtures and is excited by a longitudinal glow discharge. The pressure of the gas mixtures is varied from 100 to 1500 Pa,
and the discharge power falls into the range 15–250 W. The source (lamp) emits in the spectral interval 200–390 nm, which
covers the spectral line of the iodine atom at 206.2 nm, the spectral band of XeI(B-X) with a maximum at 253 nm, and the spectral band of with a maximum at 342 nm. For He(Xe)-I2 mixtures at a pressure of 800–1000 Pa (this pressure range is near-optimal according to our experimental data), the electron
energy distribution functions and the electron kinetic coefficients as functions of parameter E/N (E is the electric field strength, and N is the particle concentration in the discharge) are calculated. The calculated plasma parameters are used in the qualitative
analysis of key electronic processes in the plasma of an exciplex halogen UV source and will be subsequently employed in numerical
simulation of the process kinetics and output characteristics of a UV source based on helium-iodine or xenon-iodine mixtures. 相似文献
6.
K. S. Gochelashvili A. V. Dem’yanov O. N. Evdokimova I. V. Kochetov G. F. Makarenko 《Bulletin of the Lebedev Physics Institute》2013,40(6):137-144
A self-consistent numerical model for the self-sustained high-current pulsed discharge is constructed based on the solution of the equations of the population of H2 electronic and vibrational states. The model accounts for electronic, ion-molecular, and vibrational kinetics, electron attachment to and detachment from the H2 molecule, Lyman and Werner band emission, and their radiation trapping. The equations of electron-vibrational kinetics are solved simultaneously with the Boltzmann equation for the electron energy distribution function and the external electrical circuit equations. 相似文献
7.
Conventional radio-frequency (rf) nonthermal atmospheric plasmas are generated in a millimeter gap. In this Letter, we present a self-consistent numerical study of rf atmospheric microplasmas in a submillimeter gap comparable to their sheath thickness. It is shown that the narrow electrode gap deforms the discharge structure, ultimately removing the bulk-plasma region and disabling electron trapping. Significantly, these properties permit rf atmospheric microplasmas to operate at very high current densities thus simultaneously achieving higher stability and greater chemical reactivity. 相似文献
8.
Jong-Chul Park Bongkoo Kang 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1997,25(3):499-506
Magnetic and collisional effects on capacitive radio frequency (RF) discharges for magnetically enhanced reactive ion etching (MERIE) are investigated. Using simplified plasma and sheath models, a collisional magnetic-sheath equation that governs the sheath dynamics under a de magnetic field crossed with a sinusoidal RF electric field is obtained. The sheath equation includes global effects of the bulk plasma. Together with the power-balance equation and the particle-conservation equation, the sheath equation is used to extract a circuit model and predict the electrical behavior of MERIE reactors. Numerical results on the plasma density and the power in MERIE reactors agree well with reported experimental results and the circuit model describes the repeated discharge properties well 相似文献
9.
Yu. Ya. Volkolupov M. A. Krasnogolovets M. A. Ostrizhnoi V. I. Chumakov 《Technical Physics》2001,46(9):1202-1204
The characteristics of a spark atmosphere discharge initiated at an interelectrode voltage U=500 kV and a discharge initiated with a thermally bursting wire are studied. 相似文献
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Both high and low frequency relaxation oscillations have been observed in an argon capacitive discharge connected to a peripheral grounded chamber through a slot with dielectric spacers. The oscillations, observed from time-varying optical emission of the main discharge chamber, show, for example, a high frequency (46 kHz) relaxation oscillation at 100 mTorr, with an absorbed power near the peripheral breakdown, and a low frequency (2.7-3.7 Hz) oscillation, at a higher absorbed power. The high frequency oscillation is found to ignite a plasma in the slot, but usually not in the periphery. The high frequency oscillation is interpreted by using an electromagnetic model of the slot impedance, combined with the circuit analysis of the system including a matching network. The model is further developed by using a parallel connection of variable peripheral capacitance to analyse the low frequency oscillation. The results obtained from the model are in agreement with the experimental observations and indicate that a variety of behaviours are dependent on the matching conditions. 相似文献
12.
M. A. Sultanov 《Journal of Applied Spectroscopy》1966,5(5):422-425
Two supersonic jets interact to produce a dense plasma, which has marked effects on the structure and spectrum. Flow from the dense region produces marked radial inhomogeneity. The emission spectrum of the dense zone consists of a strong continuum together with asymmetrically broadened lines of the elements present in the electrodes.I am indebted to L. I. Kiselevskii for direction in this work. 相似文献
13.
O. S. Vaulina A. A. Samarian B. James O. F. Petrov V. E. Fortov 《Journal of Experimental and Theoretical Physics》2003,96(6):1037-1044
Spatial variation of dust particle charges are estimated numerically for typical laboratory experiment conditions in a radio-frequency (rf) capacitive discharge. The surface potentials of macroparticles levitating in the upper part of the near-electrode layer of the rf discharge are measured. A model is proposed for the formation of irregular dust oscillations due to stochastic motion of dust in the bulk of a spatially inhomogeneous plasma (in the presence of a dust charge gradient). This mechanism is used for analyzing the results of measurements of the amplitude of vertical vibrations of dust particles in the near-electrode layer of the rf discharge. It is found that the dust charge gradient may be responsible for the development of such vibrations. 相似文献
14.
I. A. Kryachko S. I. Tyutyunnikov V. N. Shalyapin 《Physics of Particles and Nuclei Letters》2008,5(5):462-468
It is shown that in the discharge plasma of the atomic emission spectrometer, the formation of CN molecules from CO2 and N2 takes place. The correctness of measuring the CO2 concentration from the emission intensity of CN at a wavelength of 388.3 nm in respiratory processes is proved experimentally. 相似文献
15.
Wood B.P. Lieberman M.A. Lichtenberg A.J. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1995,23(1):89-96
In capacitively coupled radio frequency discharges, the electrons gain and lose energy by reflection from oscillating, high voltage sheaths. When time-averaged, this results in stochastic heating, which at low pressure is responsible for most of the electron heating in these discharges. Previous derivations of stochastic heating rates have generally assumed that the electron distribution is a time-invariant, single-temperature Maxwellian, and that the sheath motion is slow compared to the average electron velocity, so that electrons gain or lose a small amount of energy in each sheath reflection. Here we solve for the stochastic heating rates in the opposite limit of fast sheath motion and consider the applicability of the slow and fast sheath equations in the intermediate region. We also consider the effect of a two-temperature Maxwellian distribution on particle balance and the effect of a time-varying temperature on the heating rates and densities 相似文献
16.
D. V. Rybka E. Kh. Baksht M. I. Lomaev V. F. Tarasenko M. Krishnan J. Thompson 《Technical Physics》2005,50(2):270-273
Emission characteristics of a high-current pulsed discharge in xenon are studied experimentally. The study is aimed at developing
a source of spontaneous UV radiation (with λ ≤ 250 nm) for controlling highvoltage crystalline diamond switches. 相似文献
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Yu. A. Evchenko D. V. Krasovitskii V. F. Papakin A. G. Khasabov 《Russian Physics Journal》1984,27(5):411-415
The dynamics of the velocity distribution function of the electrons in a pulsed discharge is analyzed, taking account of the initial stage of electron heating within the framework of the BGK model integral. It is assumed that the basic contribution to the relaxation of the electron distribution function comes from elastic collisions with neutral particles. The dynamic distribution function obtained is used to determine the ionization coefficient and study the dynamics of electron-cascade development.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, pp. 70–75, May, 1984.In conclusion, Prof. V. B. Krasovitskit must be thanked for fruitful discussion and constant interest in the work. 相似文献