Au等离子体M带5f-3d跃迁的电子离子碰撞激发速率系数

电子离子碰撞激发速率系数在超组态碰撞辐射模型中真实模拟非局域热动力学平衡Au激光等离子体M带谱 5f 3d跃迁中各种复杂电荷态离子的电离态特性 (譬如离子的平均电离度 ,相对丰度和能级布居数 )是必不可少的。基于准相对论多组态Hartree Fock方法和扭曲波玻恩交换近似 ,采用自编的扭曲波程序ACDW (9)和Fit(9) ,从头计算了Au等离子体M带 5f 3d电子离子碰撞激发速率系数。结果表明 :在“神光II”实验装置诊断的电子温度约 2keV ,电子密度约 6× 10 2 1cm-3 范围内 ,这些电子离子碰撞激发参数有利于采用超组态碰撞辐射模型模拟Au的激光等离子体M带 5f～ 3d细致谱的平均电离度和电荷态分布。     

Au等离子体M带5f-3d跃迁的电子离子碰撞激发速率系数

电子离子碰撞激发速率系数在超组态碰撞辐射模型中真实模拟非局域热动力学平衡Au激光等离子体M带谱5f-3d跃迁中各种复杂电荷态离子的电离态特性(譬如离子的平均电离度,相对丰度和能级布居数)是必不可少的。基于准相对论多组态Hartree Fock方法和扭曲波玻恩交换近似,采用自编的扭曲波程序ACDW（9）和Fit(9),从头计算了Au等离子体M带5f-3d电子离子碰撞激发速率系数。结果表明：在“神光II”实验装置诊断的电子温度约2keV,电子密度约 6×1021cm-3范围内,这些电子离子碰撞激发参数有利于采用超组态碰撞辐射模型模拟Au的激光等离子体M带5f-3d细致谱的平均电离度和电荷态分布。     

Characteristics of anodic glow pulsed plasma

Using the triple Langmuir probe, the characteristics of the glowing plasma adjacent to a constricted anode is obtained. The glow discharge is generated by applying a train of high voltage pulses between the constricted anode and cylindrical cathode with a pulse frequency of 2 kHz at 50% duty cycle. The axial plasma characteristics along the central line of the anode shows crest and trough resembling a double layer. The bulk plasma showed uniform electron density outside the glow. The visual images show an enhancement in the volume of the glow consistent with the discharge current. The mechanism behind the particular double layer characteristics around the anode is being explained in detail.     

Electron impact excitation rate coefficients of N II ion

This paper calculates the electron impact excitation rate coefficients from the ground term 2s²2p^{2 3}P to the excited terms of the 2s²2p², 2s2p³, 2s²2p3s, 2s²2p3p, and 2s²2p3d configurations of N II. In the calculations, multiconfiguration Dirac--Fork wave functions have been applied to describe the target-ion states and relativistic distorted-wave calculation has been performed to generate fine-structure collision strengths. The collision strengths are then averaged over a Maxwellian distribution of electron velocities in order to generate the effective collision strengths. The calculated rate coefficients are compared with available experimental and theoretical data, and some good agreements are found for the outer shell electron excitations. But for the inner shell electron excitations there are still some differences between the present calculations and available experiments.     

大气压辉光放电研究现状及应用前景

大气压辉光放电由于均匀性好、能量效率高并且不需要真空系统，正日益受到人们重视和研究．文章综述了大气压辉光放电的研究进展，包括实验条件、放电特征、放电机理以及最新的诊断方法，还介绍它在薄膜沉积、材料表面改性、污染物质的消毒去污等方面的应用前景．     

Langmuir双探针诊断Ne辉光放电管电子密度

应用Langmuir双探针诊断理论,对充有氖气的石英放电管中的辉光放电等离子体进行了诊断,通过实验测得伏安特性曲线,计算得出电子温度和电子密度,讨论了等离子体的宏观参量与电子温度和电子密度的关系.采用直径为0.1 mm的探针对等离子体进行诊断,不仅减小了对所测等离子体区域的扰动,而且减小了读取伏安特性曲线所带来的误差.     

激光金等离子体的电子离子碰撞电离速率系数

电子离子碰撞电离过程在超组态碰撞辐射(SCROLL)模型中真实模拟非局域热动力学平衡(non-LTE)高Z材料Au激光等离子体M带谱5f-3d跃迁中各种复杂离子的电离态特性,诸如离子的平均电离度和电荷态分布是一个主要过程.基于准相对论扭曲波玻恩交换近似,采用组态平均的方法,从头计算了金M带类铁金离子-类锗金离子的电子离子碰撞电离速率系数,其中电离截面的高能行为由Bethe系数决定.结果表明:在"神光Ⅱ"实验装置诊断的电子温度～2keV,电子密度～6×1021cm-3范围内,这些参数有利于使用超组态碰撞辐射模型拟Au的激光等离子体M带细致谱5f-3d跃迁的平均电离度和电荷态分布.     

大气压氩气介质阻挡辉光放电的一维仿真研究

为了研究氩气(Ar)中介质阻挡大气压辉光放电(APGD)的放电机理, 通过建立一个一维的多粒子自洽耦合流体模型, 采用有限元方法进行数值计算, 得到了气体间隙压降、介质表面电荷密度、放电电流密度随时间的周期变化波形, 以及电子、离子、亚稳态粒子密度和空间电场强度的时空分布. 仿真计算结果表明：介质表面积聚的电荷对于放电的过程的起始及熄灭具有重要作用;当增大外施电压时, 放电击穿时刻提前, 放电电流密度和介质表面电荷密度峰值增大, 表明放电过程更加剧烈;随着阻挡介质相对介电常数的增大, 放电电流密度也随之增大. 各粒子密度及电场的时空分布表明放电过程在外施电压半个周期中只有一次放电, 且存在明显的阴极位降区、负辉区、等离子体正柱区等辉光放电的典型区域, 为大气压辉光放电(APGD).     

Glow discharge in helium at atmospheric pressure as a source of spectrum excitation

Self-maintained glow discharge at atmospheric pressure in a helium flow is used as an excitation source of spectra for analysis of the metals Na, Ca, Pb, Cd, and Zn in aqueous solutions of their salts. The intensities of the analytical lines of these metals are obtained as a function of the concentration, and the detection limits for each element are determined. Deceased. Institute of Molecular and Atomic Physics, Academy of Sciences of Belarus, 70, F. Skorina Ave., Misnk, 220072, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 6, pp. 711–715, November–December, 1997.     

Emission characteristics and parameters of a glow discharge in an argon-xenon-chlorine mixture

We present the results of a study of the emission characteristics of a low-pressure longitudinal glow discharge in an Ar-Xe-Cl₂ mixture (p = 0.5–6.0 kPa) and numerical modeling of its plasma parameters as a function of the parameter E/P. We optimized the average emission power of the discharge in the spectral range 160–310 nm as a function of the discharge current, the pressure and composition of the gas mixture. The plasma parameters were calculated for the optimal mixture (according to experimental data) and included obtaining the dependences of the electron transport and energy characteristics, the power losses per unit pressure in the discharge going toward elementary electron processes in the plasma, and also the ionization and attachment coefficients as a function of the parameter E/P. The results of numerical modeling of the glow discharge parameters allow us to provide a qualitative basis for the emission distribution in the spectrum of a plasma based on an Ar-Xe-Cl₂ mixture. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 4, pp. 563–567, July–August, 2008.     

大气压Ar／NH3介质阻挡辉光放电的仿真研究

为了研究火气压下氩气（Ar）中掺杂氨气（NH3）的Ar／NH3介质阻挡辉光放电的放电机理,通过建立一‘个多粒子的自洽耦合流体模型,采用有限元方法进行数值计算,得到了气体间隙压降、介质表面电荷密度、放电电流密度随时间的周期变化波形,以及带电粒子、中性粒子与空间电场强度的时空分布．仿真计算结果表明：气体间隙的周期击穿过程主要由气隙电压控制,并受气隙两侧介质极板上积聚的表面电荷的影响．气隙间带电粒子密度和电场强度的时空分布表明本文的放电过程存在阴极位降区、负辉区、法拉第暗区、等离子体正柱区等辉光放电的典型区域,放电模式为大气压辉光放电．在Ar/NH3等离子体中,主要的正离子为NH＋,其次为Ar2＋,主要的负离子为NHi：NH3分解产生的主要的激发态分子为NH,NH2和N2H3,而最终的稳态产物主要是N2和H2．     

Spectropolarization investigations of the region of the cathode drop in the potential of a helium glow discharge at atmospheric pressure

The dimensions of the region of the cathode drop in potential in a helium glow discharge at atmospheric pressure (in Kiselevskii’s plasma source) are determined. Using Stark spectroscopy of the Balmer-series hydrogen line H_β the spatial distribution of the constant and variable components of the electric-field strength is measured. Institute of Molecular and Atomic Physics, National Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 3, pp. 362–368, May–June, 1999.     

Morphology and molecular structure of polyurethane films treated with a glow discharge plasma

We have determined the major physicochemical changes occurring in polyurethane surface layers when treated in a glow discharge plasma. We have shown that along with etching and degradation processes in the polymer, there is also redistribution of hydrogen bonds as well as an increase in the concentration of carbonyl groups and the degree of self-association of urethane fragments. We conclude that the established physicochemical changes are due mainly to selective etching of the surface layers on exposure to UV radiation and the flux of charged particles generated in the glow discharge. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 6, pp. 785–789, November–December, 2007.     

Detailed comparison between probe density measurements of glow discharge in argon and in helium

In this article we shall look a bit more closely at some of the fundamental plasma parameters obtained by a cylindrical Langmuir probe within low-pressure electrical gas discharge plasma. The presented measurements were made in argon and in helium glow discharge plasmas. We are mainly concerned with the densities of the charged particles (electrons and ions) within the plasma and the effect of the discharge conditions upon them. The electron density is calculated from the electron current at the space potential and from the integration over the EEDF. The ion density is calculated by using the OML collisionless theory. The parameterization of Laframboise's numerical results is also used for the ion density calculation. In the range of our experimental conditions the results of plasma density, for both gases, tend to show that the ion densities measured with the OML and Laframboise theories exceeds the measured electron densities. The results also show that the plasma electron and ion densities increased with both discharge power and gas pressure.     

等电位辉光放电电子温度的光谱测量与计算

用SII- IV 型全息凹面光栅单色仪对各种工艺参数条件下双层辉光等电位放电的发射光谱的相对强度进行了测量, 获得一系列光谱谱线。通过对玻尔兹曼方程式的计算, 得到了不同工艺条件下等离子放电时的电子温度。分析了工件电压、工作气压对电子温度的影响。结果表明: 在本工艺条件下, 电子温度随着工件电压的升高, 先减小后增大, 然后又减小, 并随着工作气压的增大而单调增大。工作气压的变化较工件电压的变化对电子温度的影响大。     

Electron impact excitation of hydrogen and helium in Coulomb-projected Born methods

Coulomb-projected Born methods for the theoretical study of electron impact excitation of hydrogen and helium are reviewed. The results obtained by using different forms of Coulomb-projected Born methods are compared with other theoretical and experimental results and analyzed. The inadequacy of the variable charge Coulomb-projected Born approximation (VCCPB)—the most recent form of the Coulomb-projected Born methods—in giving good results in processes where exchange is dominant is discussed in detail. The ‘modified’ VCCPB approximation obtained by modifying the VCCPB method to remove its shortcomings is also discussed and its application to electron impact excitation of 2³ s state of helium is studied.     

Electron impact ionization of SiCl<Subscript>2</Subscript> and SiCl

We measured absolute partial cross sections for the formation of all singly charged positive ions produced by electron impact on SiCl₂ and SiCl from threshold to 200 eV using the fast-neutral-beam technique. Some of the cross section curves exhibit an unusual energy dependence with a pronounced low-energy maximum at an energy around 30 eV, which may be indicative of the presence of indirect ionization channels. Dissociative ionization channels are dominant for both species. The experimentally determined total single ionization cross sections for both species agree very well with calculated cross sections using the Deutsch-M?rk (DM) formalism. A brief summary of the ionization cross sections determined for all four SiCl_x (x=1–4) species is given highlighting similarities and differences.     

细长金属管内产生的直流辉光等离子体发射光谱诊断

利用发射光谱法对金属管内形成的稳定氩氮直流辉光等离子体进行了诊断。通过对等离子体发射光谱谱线的研究确定了等离子体中的活性粒子成分;根据氩原子的玻尔兹曼曲线斜率法计算了等离子体中的电子激发温度;采用氮分子第二正带系跃迁(C3Π_u→B3Π_g)的发射谱线计算了等离子体中的氮分子振动温度;研究了电子激发温度和氮分子振动温度随压强的变化特征。研究结果表明,在20 Pa下产生的Ar60%+N₂40%直流辉光等离子体中,活性成分主要是Ar原子、Ar离子、N₂的第二正带系跃迁(C3Π_u→B3Π_g)和N+₂的第一负带系跃迁(B2Π+_u→X2Σ+_g);电子激发温度约为(15 270±250)K;氮分子(C3Π_u)振动温度约为(3 290±100)K;随着压强的增加电子激发温度、分子振动温度逐渐降低。文章的研究结果对细长金属管内表面改性研究具有重要的意义。     

大气压下石英毛细管内氩等离子体放电的发射光谱诊断

在长度为20 cm的石英毛细管内利用两个边缘锋利的中空的针型电极之间的氩气放电产生了高电子密度的大气压等离子体。利用发射光谱对所获得的等离子体的几个重要参数进行了诊断。利用计算机谱线拟合法合成了300 nm附近OH(A-X)的(0-0)转动谱带并通过与测量谱线的比较确定了等离子体的气体温度,根据H_β谱线Stark展宽法计算了等离子体的电子密度,采用玻尔兹曼曲线斜率法依据测得的有关氩的发射光谱估算了等离子体的电子温度。研究结果表明,这种石英毛细管内弧光放电等离子体的气体温度约为(1 100±50)K;电子密度数量级在1014 cm-3;电子温度约为(14 515±500)K。