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1.
We study the influence of longitudinal magnetic field on the radiation of low-pressure glow discharges in hydrogen and helium. We conducted experiments under a pressure in a discharge chamber of 10–20 Pa and a discharge current of 10–20 mA. A 0–1600 G magnetic field influenced only the cathode parts of the discharge, negative glow, and the dark Faraday space. The electron temperature and density were measured by the two-probe method as a function of magnetic field. We studied the dependence of the intensity of radiation in the spectral lines and continuous spectrum on magnetic field induction. We discovered that, under the action of magnetic field, discharge in hydrogen and helium is compressed and its glow volume increases by a factor of 20–25. In contrast, the radiation intensity in the lines and continuous spectrum increase by a factor of 100–200. We found a strong discrepancy in the measured intensity of the continuous spectrum into spectral ranges with calculation of electron-ion recombination.  相似文献   

2.
Longitudinal distributions of plasma parameters in a short (free of positive column) glow discharge in helium show evidence for the formation of a potential well for thermal electrons and the reversal of electric field in plasma of negative glow and Faraday dark space. Depending on the reduced discharge length pL, one or two points of field reversal can appear, which determines the sign of the anode fall.  相似文献   

3.
The influence of a longitudinal magnetic field on electron temperature and density and on the continuous spectral radiance of a negative glow discharge in the visible spectrum range was studied. The electron temperature and density were determined by the double probe method. It was found that the discharge is compressed to a narrow column under the action of the magnetic field and its glow intensity increases by ~100 times. This is accompanied by an increase in the electron temperature and density. The total voltage at the discharge decreases by two or three times. The study of the influence of a longitudinal magnetic field on the spectral radiance of the continuous spectrum is of greatest interest in this work. For the given conditions of the studied glow discharge (low pressure and small degree of ionization ~10?6), bremsstrahlung radiation was shown to make the largest contribution to continuous spectral radiance upon electron scattering on a neutral particle. The measured quantity of the continuous spectral radiance of the discharge was compared with the calculated quantity of bremsstrahlung radiation for neutral particles. The measured quantity was found to be larger than the calculated one by 102–103 times, and the largest discrepancy was observed in the absence of the magnetic field. A hypothesis is proposed to explain such a strong discrepancy between the measured and calculated spectral radiance of the continuum spectrum.  相似文献   

4.
Results of investigation of a high-current plane pulsed surface discharge with separated torches fired in the air at atmospheric pressure are presented. The dynamics of ignition and development of the discharge in the prebreakdown stage has been considered. The main parameters of the plasma in the prebreakdown stage (the stage of intense prebreakdown glow) have been determined by spectroscopic methods and the influence of the dielectric material of a substrate on the plasma parameters has been analyzed. It has been established that the duration of an intense prebreakdown glow depends on the experimental conditions. A physical pattern of formation of an intense prebreakdown glow is proposed.__________Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 78, No. 1, pp. 178–185, January–February, 2005.  相似文献   

5.
The results are given of an investigation of the output characteristics of an electric-discharge excimer-halogen UV emitter utilizing a Xe/Br2/J2 mixture. A longitudinal glow discharge with an interelectrode spacing of 50 cm and inside diameter of the discharge tube of 1.4 cm is ignited at the working mixture pressure of 1 kPa and power input to the plasma of 10–350 W. A study is performed of the current-voltage characteristics of the discharge, plasma radiation spectra in the 190–350 nm range, and distributions of the brightness of radiation of molecules as a function of the pumping conditions, as well as of pressure and partial composition of the gas mixture. It is demonstrated that the plasma of the discharge being investigated is a source of broadband UV radiation in a system of bands of 253 nm XeJ, 282 nm XeBr, and 292–310 nm Br2 *, which are joined by the radiation of resonance line of iodine atom with = 206 nm. The total power of UV radiation of plasma increases linearly with the electrical power of the glow discharge.  相似文献   

6.
Some New Views on the Principles of Magnetron Sputtering   总被引:1,自引:0,他引:1  
In this paper, some common phenomena in magnetron sputtering are freshly analyzed and discussed on the basis of the motion of electrons in non-uniform orthogonal electric and magnetic fields. There exist magnetic confinements in three spatial dimensions on moving charged particles (including electrons) in this kind of non-uniform field. They are the longitudinal cycloidal motion, the horizontal simple harmonic-like motion (with varying amplitudes), and the vertical repelling action. The horizontal magnetic confinement in a mirror-like magnetic field keeps glow discharge lane completely parallel to the corridor of magnetic force lines, therefore only an effectively closed magnet array structure can form a relatively uniform and closed discharge lane. The main reasons for electrons' releasing from magnetic confinement are the vertical magnetic repelling force as well as a more and more weak confinement action in outer range etc. The dominant reasons for a comparatively low increase of substrate's temperature are that the density of bombarding electrons near the substrate is relatively low and their spatial distribution is relatively uniform (compared with that near the target surface). The erosion lane with an inverted Gauss's distribution shape on a magnetron sputtered target is due to that,with sputtering, the distribution width of the critical density of electrons shrinks continuously but the sputtering effect in the centerline of the corridor is always the most powerful.  相似文献   

7.
No Heading Multielectron bubbles in liquid helium contain a spherical two-dimensional shell of electrons at the bubble surface. We investigate the properties of this electron gas when the bubble is placed in a homogeneous magnetic field. Results are reported for the Fermi level and the magnetization of the bubble. At high field, we find the formation of Landau bands rather than Landau levels.PACS numbers: 73.20.Qt; 73.20.–r; 64.70.Dv; 68.35.Ja; 47.55.Dz  相似文献   

8.
Results of a three-dimensional direct statistical simulation of formation and energy relaxation of a group of high-energy electrons in cathode regions of the low pressure (p < 1 Torr) glow discharge in helium are given. It is demonstrated that the electron distribution function at the exit from the cathode sheath contains a group (beam) of high-energy electrons which did not suffer inelastic collisions and had energy close to the cathode fall potential. The beam is shown to be a main source of charged particle production in the negative glow region. The calculated electron energy distribution function is compared with experimental data.  相似文献   

9.
We present the working characteristics of a high-power UV-VUV electric-discharge lamp filled with a working mixture of helium and iodine vapor (He-I2) at a low pressure (0.1–1.5 kPa) and pumped by a dc glow discharge at a power of 15–200 W. The power of the total output UV radiation and the main emission peak at λ = 206.2 nm were studied as dependent on the electric power supplied to the glow discharge and on the partial pressure of helium in the He-I2 mixture. The emission characteristics of the glow discharge plasma were studied in the spectral range from 200 to 350 nm. In this range, the lamp is operating predominantly on a resonance emission line of excited iodine atoms (λ = 206.2 nm, FWHM = 0.10–0.12 nm) and on a system of electronic-vibrational bands of excited iodine molecules with the main peak at λ = 342 nm. The contribution of the resonance emission due to excited iodine atoms to the total UV emission from the glow discharge plasma does not exceed 50%. The optimum partial pressure of helium is within 400–800 Pa. The total UV radiation power of the lamp operating in the optimum regime reaches 25 W at an efficiency of η ≤15%.  相似文献   

10.
The optical regularities of the development of the plasma channel of a high-pressure pulse discharge are investigated in the presence of high gradients of magnetic field at the plasma–neutral gas interface (P H 109 Pa/m) and a low inductance per unit length of the discharge circuit (L 10–4 H/m). It is shown that, when the rate of delivery of electric energy into the discharge gap varies and in the presence of intensity of external magnetic field, the dynamics of zones of high conductivity and brightness of glow change significantly. The behavior of the temporal evolution of the distribution of the radiation intensity over the spectrum in the optical range is studied.  相似文献   

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