Influence of the Electric Field Enhanced Thermal Electron Emission on Temperature of the Cathode with a Thin Insulating Film in the Arc Gas Discharge

Technical Physics - A model of the electric field enhanced thermal (thermo-field) emission of electrons from the metal cathode substrate into a thin insulating film on its surface is developed. A...     

Electron Emission Suppression from Cathode Surfaces of a Rod-Pinch Diode

The theory and method of suppressing electron emission from cathode surfaces is introduced, including increasing the emission threshold, reducing the surface electric field and shielding the emitted electrons. The stainless steel-graphite and Teflon-graphite composite cathodes are designed to test the above methods for a rod-pinch diode. The experiments are performed on the inductive voltage adder, and the results indicate that the Teflon-graphite composite cathode is effective in suppressing electron emission from the specified cathode surface, while the stainless steel-graphite composite cathode fails. The reasons are analyzed theoretically.     

High-Efficiency Electron Source with a Hollow Cathode in Technologies of Thin Film Deposition and Surface Treatment under Forevacuum Pressures

It is shown that low-energy beams with a high efficiency in a wide range of beam currents can be obtained in electron sources with a hollow cathode in the forevacuum pressure range. By varying the geometrical parameters of the electrode system and electromagnetic optics of the electron source, we succeeded in reaching the efficiency at a level of 0.9 for an accelerating potential of 1 kV and beam currents from 100 to 300 mA. The parameters affecting most strongly the efficiency and stability of operation of the electron source with a hollow cathode have been determined.     

栅极和阴极的相对高度对电子传输比的影响

用边界元法(BEM)和Monte Carlo方法,对一种基于碳纳米管场发射大面积彩色平面型显示器的电子传输比进行了理论分析,通过模拟跟踪发射电子轨迹,证实改变阴极和栅极的相对高度,可以较大幅度地提高电子传输比阳极上电子的分布证实,我们设计的显示器结构能够满足高分辨率、高亮度的显示的要求,而且驱动电压低,工艺简单。     

Electron Energy Distribution and Optical Characteristics of a Hollow Cathode Discharge

A model is proposed for the formation of the electron energy distribution in a hollow cathode discharge. On the basis of this model, an integral equation has been derived to calculate the electron distribution function over the entire cathode cavity volume. The equation holds true for both the isotropic distribution, and the case when the local distribution function is anisotropic. Solutions of the kinetic equation obtained are presented, for electron energies over 2–3 eV and up to the cathode fall potential. It is shown that the electron energy distribution function in this interval determines the optical characteristics of the hollow cathode discharge. A comparison is given of the calculated and measured radiation powers for the cases of the hollow cathode discharge in xenon and carbon dioxide. The discrepancy between the theoretical and experimental data does not exceed 20%.     

Electron Kinetics in the Cathode Region of a Glow Discharge and in Hollow Cathodes

On the basis of an improved cascade model a multi-group theory for studying the electron kinetics in the cathode region of a glow discharge and in hollow cathodes is developed. The secondary electrons newly created by ionization are taken into account. The electrons are divided in groups with respect to the interval where they were created or where they made an inelastic collision. The inelastic collisions and the forward scattering are assumed to dominate. The mean energies of two neighbouring groups are taken to be different by the ionization energy or by parts of it. For the flux densities of the various electron groups a set of ordinary first order differential equations and corresponding boundary conditions are obtained and solved for He. These formulae are valid for any electric potentials. The results relatively well agree with those of Monte Carlo simulations. The first Townsend ionization coefficient differs substantially from that resulting from the Townsend formula. The velocity distribution function spatially varies and contains several groups of fast electrons. Using the detour factor the angular scattering can be included in the calculations.     

氮气交流放电光谱强度和电压及气压的关系

利用浓度调制光谱技术,测量了玻璃管中放电频率20 kHz时N2的介质阻挡放电光谱.实验记录了N2的C3∏u-Bb∏g357.7nm和B2∑ u-X2 g391.4 nm的跃迁谱线光谱强度随小同电压和气体压强变化规律.实验数据显示,保持气体压强p=130 Pa不变,在电压较低时,光谱强度随电压增长较快,在电压较高时,光谱强度增长较慢;保持放电电压U=6.4 kV不变,光谱强度随气压增长逐渐变小.根据电子和分子碰撞激发函数和电离函数,建立光强随放电参数变化的物理理论模型和公式,并对实验数据进行数学拟合,拟合曲线与实验结果符合较好,相关系数R>0.9.进一步明确了等离子体发射光谱强度随不同电压和气体压强变化的机理.     

Optical Probing of the Electron Energy Function Distribution in a Photoresonant Hollow Cathode Discharge

Optical probing of electron gas in photoresonant negative glow is considered. By monitoring the spectral line intensity it can be concluded that the transfer of excitation energy to the probe atoms is mainly due to the electron gas.     

Multipoint Ignition of a Gas Mixture by a Microwave Subcritical Discharge with an Extended Streamer Structure

The results of experimental studies on using an electrical discharge with an extended streamer structure in a quasioptical microwave beam in the multipoint ignition of a propane–air mixture have been reported. The pulsed microwave discharge was initiated at the interior surface of a quartz tube that was filled with the mentioned flammable mixture and introduced into a microwave beam with a subbreakdown initial field. Gas breakdown was initiated by an electromagnetic vibrator. The dependence of the type of discharge on the microwave field strength was examined, the lower concentration threshold of ignition of the propane–air mixture by the studied discharge was determined, and the dynamics of combustion of the flammable mixture with local and multipoint ignition were compared.     

Influence of the Anode of a Non-Self-Sustained Glow Discharge with a Hollow Cathode on the Spatial Distribution of Plasma Concentration

Russian Physics Journal - The results of investigation of the influence of geometrical dimensions, shape and position of the anode of a high-current non-self-sustained glow discharge with a hollow...     

Influence of the Discharge Burning Conditions on Distributions of the Parameters of Plasma Generated in a Non-Self-Sustaining Glow Discharge Inside a Hollow Cathode

Russian Physics Journal - The parameters of the plasma of a non-self-sustaining glow discharge generated inside a metal hollow cathode 300 mm long and 25 mm in inner diameter are investigated. A...     

Influence of Voltage Fluctuations on Gyrotron Efficiency and Stability

Influence of power supply voltage instability on gyrotron operation regime is investigated. Dependence of efficiency versus variations of external parameters is given and conditions of oscillations cutoff are determined. It is shown that positive voltage fluctuations result in sharp falling efficiency and failure of self-oscillations and the steadiest gyrotrons are those with short cavities and the large ratio of transverse electron speed to longitudinal one around 1.5 - 2. Comparison of theoretical and experimental results is given.     

Gas-Discharge Sources with Charged-Particle Emission from the Plasma of a Hollow-Cathode Glow Discharge

The peculiarities of a magnetron discharge with a cold hollow cathode and an uncooled rod cathode are considered. It is shown that the thermionic emission of the rod cathode heated in the discharge makes a major contribution to the discharge characteristics and to the emissivity of the gas-discharge plasma and that a glow discharge can gradually change to the diffusion mode of operation of an arc discharge. Ion and electron sources with improved physical characteristics and general technical data are described. It has been demonstrated that the electrode structure of a hollow-cathode magnetron discharge holds promise not only as an emitting-plasma generator, but also as a source of atomic hydrogen and atomic flux of a consumable (sputtered and evaporated) rod cathode.     

On the Electron Emission from the Focal Region of a Symmetrically Convergent Surface Plasmonic Wave on the Free Surface of a Metal Film

Optics and Spectroscopy - Excitation and focusing of a radially convergent surface plasmonic wave on the free surface of a gold film in the Kretschmann geometry have been considered based on the...     

温度对来自镶嵌在BaO薄膜中的纳米银粒子的光电发射影响

 研究了温度对来自镶嵌在BaO薄膜中的纳米银粒子的光电发射的影响。在不同温度下计算和讨论了其光电发射谱（入射波长在0.2~0.8 μm）。光电发射谱中温度越高，光电发射峰越大。同时发现镶嵌在BaO薄膜中银纳米的临界尺寸小于3.8 nm。