电激励脉冲HF激光SF_6/C_2H_6工作气体的放电特性

研究了电激励脉冲HF激光工作介质SF6/C2H6混合气体的放电特性。通过对放电等离子体荧光图像和放电波形的测量,分析比较了不同条件下放电稳定性、剩余电压、能量沉积效率等特性参数的变化情况。实验结果表明:混合气体的放电过程存在主放电、剩余电压维持和电弧放电3个阶段,各阶段的放电特性有所差异;提高充电电压有利于放电能量的有效沉积,也会使不稳定的电弧放电提前;增加C2H6原子分数能起到抑制电弧放电的作用;混合气体总压的增加会导致剩余电压的提高以及辉光放电的能量沉积效率的降低;最佳的能量沉积出现在电弧放电阶段与辉光放电阶段即将融合的临界状态。     

Kinetic processes in the electric discharge in SF6

The simulation of the kinetic processes in the spatially homogeneous and heterogeneous plasma of the gas discharge in SF6 is performed. The calculated time dependences of the rates of the most important processes and the concentrations of electrons, ions, and other particles that affect the plasma characteristics are presented. The calculated and experimental results are compared. The kinetic processes are analyzed and their effect on the plasma characteristics is demonstrated. The calculated data regarding the development of the plasma channel are presented. An increase in the conductivity inside the channel is discussed. Original Text ? Astro, Ltd., 2006.     

Pathways in the molecular fragmentation for the C2H5OH/He electrical discharge

ABSTRACT

This study focuses on the glow discharge generated with a gases mixture of Ethanol (C₂H₅OH) and Helium (He), at different concentrations maintained at a total pressure of 2.0 Torr. We used optical emission spectroscopy (OES) to analyze the discharge mixture at different concentrations of Helium. Single Langmuir probe data was used to determine the Electron Energy Distribution Function (EEDF). For the total C₂H₅OH/He mixture plasma concentrations, the EEDF has a Maxwellian distribution function. A decrease in He concentration results in significant changes in the EEDF, this behavior is related to the increase in the C₂H₅OH percentage must increase the energy loses of the electrons in the inelastic collision with C₂H₅OH producing a significant change in the EEDF, therefore, the EEDF pattern results in an increase of electron–molecule reaction rates. The rise in electron temperature for increasing Helium percentage is explained by the decreasing electron energy loss in the inelastic collisions with C₂H₅OH molecule. It observes a decrease of electron density ne as a function of the Helium percentage, which can be related to the ratio between ionization cross sections of Helium and C₂H₆O molecule. The active species are generated in the electron-molecule processes, which are associated with electron impact dissociation of C₂H₅OH and Helium electronic impact excitation in the gas phase. The emission optical spectra (OES) show changes in the intensity of the most important peaks of the plasma mixture, which indicates the dependence in the formation of the plasma as a function of the percentage of the gases. The changes in the intensities of the same observed species are due to different processes of excitation and ionization energies of the system, in addition to the increase of He metastable states He I. Hydrogen is the main product obtained from the decomposition of C₂H₅OH.     

非链式HF激光器SF6气体介质放电特性

采用放电图像拍摄和放电波形测量两种方法研究了放电激励HF激光工作介质SF6气体的放电特性。实验结果表明：SF6气体放电可以分为主放电、剩余电压维持和电弧放电3个阶段。主放电阶段为均匀体放电,电容储能大部分在此阶段沉积于放电等离子体中;剩余电压维持阶段无明显放电;在电弧放电阶段激光器以电弧形式消耗剩余储能。通过对放电波形的分析,获得剩余电压及主放电阶段能量沉积效率随充电电压的变化规律。随着充电电压提高,剩余电压下降,沉积效率逐渐提高。沉积效率最大值对应于主放电与电弧放电相接的时刻。     

The characteristics of a negative corona discharge in He/Xe/SF6 mixture

The results of investigation of the electrical and optical characteristics of a negative corona discharge in the electrode system of the type needle-grid lit in a He/Xe/SF₆ mixture under the pressure of 100–300 kPa are presented in this paper. The given medium is working for a pulse-periodic excimer lamp on = 351 nm XeF(B–X). Distributed on the length of a lamp active media a bipolar corona discharge is intended for using in the electric circulation of the XeF-lamp working medium. It is shown that the given discharge is ignited steadily in the He/Xe/SF₆ mixture, containing 0, 5kPa SF₆ molecules and is characterised by a low power consumption; the current of the discharge is limited to the development of instability by increasing the voltage on the needles; in hot zones of corona discharge SF₆ molecules cause the effective population 6s of XeI state.     

Intensitäten myonischer Röntgenlinien in SF6 und H2 plus SF6

Muonic X-ray spectra from S and F in SF₆ and H₂+SF₆ have been measured with a high-pressure gas target. Strong differences between the observed intensities of corresponding lines were found for the two cases. The results are compared with cascade calculations. The per-atom ratio between Coulomb capture in F and S was determined to be 0.96±0.09 and 1.04±0.24 for SF₆ and H₂+SF₆, respectively.     

Critical temperature shift in pure fluid SF6 caused by an electric field

A systematic study of the effect of an electric field on the critical temperature of a pure fluid is made for the first time to our knowledge. An ac electric field is applied to a spherical capacitor filled with SF6 at its critical density, while the temperature is slowly ramped down through its critical temperature T(c). By continuously observing the light transmission through the fluid during the temperature ramp, a shift in T(c), DeltaT(c), is found at various electric fields. By shining the light vertically through the fluid, we utilize the density gradient induced by the fluid's weight to compensate for the effects of density changes from electrostriction. This technique effectively keeps the system at constant critical density with respect to the observation of T(c). We observe an increase in T(c) as expected from thermodynamic stability and renormalization group theory, but quantitatively larger by an order of magnitude.     

Thermal and electrical properties of heavy current arc column in SF6 gas

Numerical computations of the electrical properties and temperature profiles of wall-stabilized arcs in sulphur hexafluoride, SF₆, at 1 ata are presented. The voltage gradient vs. arc current characteristic curve has a minimum point at which the axial temperature is the same inherent value of the gas independent of the arc radius. Also, the radial temperature distributions up to several hundreds of amperes corresponding to the axial temperature of some 20000 °K have been computed.     

SF_6气体及其衍生物的红外光谱分析

SF6气体大量应用于气体绝缘组合电器(GIS)中。通过化学方法检测SF6气体及其衍生物是检测GIS设备故障的一种重要方法。该文采用红外光谱技术分析了三种情况下的GIS设备内SF6气体组成情况,得出S2F10气体含量可以用来分析GIS故障原因是否为强火花或者电弧放电引起;CF4气体可以用来表征GIS设备内绝缘气体的绝缘状态。另外,研究表明,GIS设备在线运行时,绝缘气体气室密封失效、造成气体泄漏,引入新的气体杂质的问题比较严重。所以在进行GIS设备维护工作时,绝缘气室的密封维护工作十分重要。文章在研究GIS设备绝缘气体SF6红外谱图的基础之上提出了建立基于红外光谱技术的GIS设备故障诊断专家系统的意见。     

High-spin states in 22Ne populated in the 14C(12C, α)reaction

The CDF Collaboration reported an excess in the production of two jets in association with a W . We discuss constraints on possible new particle state interpretations of this excess. The fact of no statistically significant deviation from the SM expectation for Z +dijet events in CDF data disfavors the new particle explanation. We show that the nucleon intrinsic strange quarks provide an important contribution to the W boson production in association with a single top quark production. Such W +t single top quark production can contribute to the CDF W +dijet excess, thus the nucleon intrinsic quarks can provide a possible explanation to the CDF excess in W +dijet but not in Z +dijet events.     

Radiation spectra of a spark discharge in mixtures of inert gases with HCl and SF6

Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 50, No. 4, pp. 556–559, April, 1989.     

Wavenumber spectra of turbulent ionization waves in Ne discharge

The one-dimensional wavenumber spectra of turbulent ionization waves were measured from the light fluctuations of the positive column. The experimentally obtained spectra were decreasing from an optimum wave number k₀ to the higher wave numbers as k^-1.6.     

Electron energy distribution function in Ne low pressure discharge

An experimental study of the electron energy distribution function in a homogeneous column of the neon low pressure discharge in dependence on the different discharge conditions (discharge current and Ne pressure) is described.The author thanks doc. dr. M.ícha for valuable discussions about this paper.     

A.C. electrical conductivity of pure and doped potassium perchlorate

A.C. electrical conductivity of potassium perchlorate (KP) has been measured in the temperature range 25–325°C at frequencies ranging from 50–500 Hz using an automated technique. The results are interpreted in terms of a novel mechanism involving Schottky defects in the anion sublattice and Frenkel defects in the cation sublattice. The conductivity behavior of KP is compared with literature data on similar low-symmetry systems containing polyatomic ions.     

Volume discharge excited by an electron beam in an Ar-SF6 mixture I. Beam-controlled discharge

Beam-controlled current flow is investigated in an Ar-SF₆ mixture at atmospheric pressure. It is shown that electron attachment to SF₆ molecules plays an important role in the charge-dparticle balance, and the attachment constant is determined. The discharge energy properties are studied.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 72–76, July, 1978.     

The production of excimer molecules and excited atoms in a positive corona discharge in He/Xe(Kr)/SF6/CCl4 mixtures

Electrical and optical characteristics of a positive corona discharge in He/Xe(Kr)/SF₆/CCl₄ mixtures, which are of interest for the use in multiwavelength excimer radiation sources, are studied in the needle-grid electrode configuration. The length of the discharge, which is usually used to pump repetitive high-pressure multiwavelength radiation sources, is equal to the length of the electrodes of an excimer laser or lamp pumped by a transverse electric discharge. The discharge current-voltage and frequency characteristics, panoramic emission spectra, and the dependences of the relative emission intensity from the halogenides and excited noble gas atoms on the corona discharge current are investigated. The main processes resulting in the production of halogenides, as well as xenon and krypton excited atoms, in the generation regions of a corona discharge are studied.     

The dependence of the electron distribution function on the discharge current in Ne and Ne-He discharge

The dependence of the shape of the electron distribution function on discharge current has been found in Ne and Ne-He low-pressure discharge by means of experimental set-up which makes possible direct record of the electron distribution function.The authors desire to acknowledge the support offered them by Professor Dr. V. Kunzl.     

Volume discharge excited by an electron beam in an Ar-SF6 mixture II. Cascade ionization discharge

The discharge investigated is initiated by an electron beam with a duration of 10^–7 sec under conditions where cascade ionization plays an important role in sustaining the current. The results obtained for the dynamics of the transition from a beam-controlled discharge to the cascade ionization mode are given. Stable discharge regions with a high specific energy input into the gas are identified.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 77–81, July, 1978.