用光谱学方法研究不同放电等离子体粒子约束

本文用光谱学方法研究在ＨＬ－１装置上ＬＨＣＤ及ＥＣＲＨ等离子体，弹丸注入等离子体，偏压电极与偏压孔栏等离子体粒子约束特性。结果表明：在弹丸注入使用正向偏压电极与偏压孔栏期间，等离子体粒子约束行到改善，较低密度下（＾ｎｅ＜２．０×１０＾１＾３ｃｍ＾－＾３），ＬＨＣＤ脉冲期间粒子约束得到改善；而当密度＾－ｎｅ大于２．０×１０＾１＾３ｃｍ＾－＾３时，等离子体约束变坏。ＥＣＲＨ脉冲期间粒子约束得不到改善。     

HL—1M装置欧姆等离子体实验的初步分析

从１９９４年１０月２４日开始，对ＨＬ－１Ｍ装置进行欧姆加热等离子体的调试实验，获得了Ｉｐ＝３１０ｋＡ，ｑｎ＜２．５，ｎｃ＝３×１０＾１３ｃｍ＾－３，Ｔｃ（０）＞１ｋｅＶ，Ｔｉ（０）＞０．５ｋｅＶ和τＥ≈１０ｍｓ的平衡稳定等离子体。本文简述了ＨＬ－１Ｍ装置及其诊断等的实验结果进行了初步分析和讨论。     

激光产生等离子体的研究

强激光（≈１０＾８－１０＾９Ｗ．ｃｍ＾－＾２）轰击固体靶产生等离子体，用４ｋＶ电势引出，得到最高总束流峰值为４．５ｍＡ，观察到离子最高电荷态为Ｃ＾３＾＋，Ａｌ＾３＾＋，Ｃｕ＾４＾＋，Ｔａ＾５＾＋，Ｐｂ＾４＾＋。另外，还详细研究了激光能数对等离子体的影响及激光等离子体的损失。     

金刚石镀膜装置中的等离子体参数测量

利用平行马赫探针和单探针对金刚石镀膜装置中的等离子体漂移速度、,离子密度及电子温度进行了测量,采用ＣｈｕｎｇＫｙｕ－Ｓｕｎ理论对平行马赫探针数据进行分析得到的马赫数为０．２８,电子温度为５ｅＶ,等离子体流速约为９８０ｍ．ｓ＾－１。单探针测行离子密度在１０＾１８～１０＾２０ｍ＾－３的范围内,电子温度在２－８ｅＶ的范围内。     

非理想Ar等离子体Hugoniot曲线研究

Ａｒ气初始压力为０．１ＭＰａ,初始温度为２９３Ｋ,Ａｒ等离子体５个实验点的压力为０．１２５－０．１６３ＧＰａ,电子密度ｎｅ≈１０＾１９ｃｍ＾－２,非理想性参数Г为０．４３－０．４５的条件下测量了非理想Ａｒ等离子体Ｈｕｇｏｎｉｏｔ曲线。冲击波速度由光谱辐射信号确定,粒子速度由实测飞片速度、阻滞法和等熵线确定。实验的Ａｒ等离子体Ｈｕｇｏｎｉｏｔ曲线与考虑二级电离效应后Ａｒ等离子体的理论ｐ－ｕ线符合得很     

超短超强激光与稀薄等离子体相互作用的数值研究

用一维粒子模拟方法（Ｐａｒｔｉｃｌｅ－ｉｎ－Ｃｅｌｌ）数值研究了超短超强激光（Ｉλ＾２〉１０＾１８Ｗ．μｍ＾２／ｃｍ＾２）与稀薄等离子体的相互作用过程，结果表明，超短超强激光与稀薄等相互作用后，在等离子体中激发起尾波和拉曼（Ｒａｍａｎ）波，它们的波长和频率的值与解析解符合得很好；同时在尾波的作用下，等离子体的部分电子被加速的很高的速度，甚至接近光速。     

HT—6B的Zeff监测及RHF对杂质约束的影响

本文通过测量ＨＴ－６Ｂ等离子体中ＯⅥ的线辐射强度随放电参数的变化，利用杂质输运分析的数值结果，给出了在等离子体参数很大的变化范围内［ｎｅ＝（０．２－２．０）×１０＾１３ｃｍ＾－３，ｑａ＝３－８．５］Ｚｅｆｆ及杂质相对浓度随放电参数的变化规律。在外加共振螺旋磁场（ＲＨＦ）抑制外撕裂模的实验中，ＯⅢ、ＣⅢ的线辐射测量表明ＲＨＦ具有改善杂质约束的迹象，此时光谱信号中反映出的相应频率的粒子扰动也被ＲＨＦ所     

铁(Ⅱ)-邻二氮菲逐级配合物的摩尔吸光系数的研究

本文用分光光度法测定铁（Ⅱ）－邻二氮菲溶液配合物各级摩尔吸光系数Δε１＝９．０３×１０＾３Ｌ·ｍｏｌ＾－１·ｃｍ＾－１,Δε２＝１．０３×１０＾４Ｌ·ｍｏｌ＾－１,其各级摩尔吸光系数的实验值Δε实验吻合较好,验证了结果的可靠性。     

高增透的类金刚石碳膜的红外吸收特性研究

利用射频等离子体分解甲烷的技术在锗片上沉积了非晶结构的类金刚石碳膜,傅里叶红外光谱仪测量显示镀覆的类金刚石碳膜的锗片在红外范围内具有高增透作用,特别在１７４０～！２０４４ｃｍ＾－１其峰值透过率高达９９％,在９４５．７ｃｍ＾－１（１０．６ｕｍ）处透过率为９４．５％。利用实测的液内的吸收系数接近于０,在１０．６ｕｍ的吸收系数为２３０ｃｍ＾－１,膜主要由ｓｐ＾３的Ｃ＿Ｈ键结构组成,各吸收峰均得到了很好的     

高TcBOLOMETER

章给出了高Ｔｃ超导红外探测器的理论分析；器件设计。并报道了用ＧｄＢａ２Ｃｕ３Ｏ７－ｘ薄膜制备的红外探测器的实验结果。得到的最好结果是噪声等效功率ＮＥＰ（５００，１０，１）＝１．４×１０＾－１１ＷＨｚ＾－１／２；探测率Ｄ＾＊（５００，１０，１）４．２×１０＾９ｃｍＨｚ＾１／２Ｗ＾－１；响应度Ｒｖ＝１０６５Ｖ／Ｗ。     

Large area planar plasma sustained by surface microwave

In this paper, we show theoretically and experimentally that the large-area planar plasma with high density and good uniformity can be sustained by a surface microwave when the electron density is over-dense. From the experimental results we find that the nonuniformities in azimuthal plasma density and electron temperature have been greatly improved and in particular the nonuniformity is less than 10{\%} when the gas pressure is 30 Pa. By improving the antenna shape, enhancing the microwave power and choosing the appropriate gas pressure, the large area planar plasma with high density can be produced.     

60MHz电容耦合等离子体中电子能量分布函数特性研究

甚高频(频率大于30 MHz)耦合放电源由于能产生大面积高密度的等离子体而受到了人们的广泛关注. 采用电流、电压探针以及朗缪尔探针诊断技术对60MHz射频激发产生的容性耦合等离子体的放电特性及电子行为进行了研究. 实验结果表明,等离子体的等效电阻/电容随着射频输入功率的增加而减小/增加;等离子体中电子行为不仅依赖于射频输入功率,还与放电气压密切相关;放电气压的增加导致电子能量概率分布函数(EEPF)从双温Maxwellian分布向Druyvesteyn分布转变,而且转变气压远低于文献所报道的数值,这主要是由于在60MHz容性耦合等离子体中电子反弹共振加热效率大为降低. 关键词： 甚高频容性耦合等离子体 朗缪尔探针诊断 电子加热模式     

Parameters of the Plasma Sheet Generated by a Sheet Beam in the Range of Forvacuum Pressures

Results of experimental investigations into the spatial distribution of the parameters of the plasma (electron concentration and temperature) generated by a sheet beam with energy up to 2 keV in argon at pressures from 6 to 9 Pa are presented. The electron beam was produced by a source with a plasma cathode specially designed for emission of beams in the range of forvacuum pressures. It is demonstrated that the character of distribution of the plasma parameters is caused by the corresponding distribution of the electron current density over the beam cross section, and the plasma parameters themselves also noticeably depend on the gas pressure and the magnetic field. A model of ionization processes that provides satisfactory agreement between the calculated and experimental dependences is suggested.     

Formation of a pulsed electron beam in a plasmacathode system under forevacuum pressures

Results of an experimental study of the features of the production of pulsed beams by a plasma electron source operating in the forevacuum pressure range (5–15 Pa) are presented. For this pressure range, the emission properties of the plasma are substantially affected by the backward ion flow generated in the regions of formation and transport of the electron beam. It has been shown that in experimental conditions the ratio of the current of backward ions to the current of the electron beam can reach 10%, which is an order of magnitude greater than the same parameter for electron sources operating in the pressure range that is conventional for devices of this type (0.01–0.1 Pa). The principal factors that impose an upper limit on the beam current in a plasma-cathode source are analyzed.     

High-Energy Electron Production by Vp × B Acceleration in Microwave-Plasma Interaction Experiments

Detailed experimental observations on the microwave plasma interaction in a nonuniform plasma with weak magnetic field (?/? ? 10-2) have revealed that high-energy electrons are produced by a process of the VP × B acceleration, where ? and ? are, respectively, electron cyclotron and microwave frequencies. The maximum energy of hot electrons increases almost linearly to about 1 keV with the RF power up to 8 kW. Hot electrons are produced from typically two regions; one in the underdense region (several centimeters down the critical layer for the resonance absorption) and the other in the resonance absorption area. The theoretical predictions have interpreted the experimental results in reasonable agreement.     

用于半导体加工的腔耦合－磁多极型ECR源的研究

本实验室研制出一台谐振腔耦合一多极场位形的电子回旋共振（ＥＣＲ）微波等离子体源（ＭＥＰ）。采用朗谬探针和离子能量分析器，测量了ＭＥＰ中Ａｒ等离子体的放电特性。实验结果表明．ＭＥＰ能在很宽的运行参数范围，高效率地产生具有较高密度、较低离子温度和空间电位的大面积均匀等离子体，特别适合于半导体加工应用研究。     

强流电子束碰撞电离背景气体研究

利用数值计算与粒子模拟两种方法,结合实际的实验数据,对高功率微波二极管中相对论电子束与背景气体相互作用碰撞产生的等离子体密度进行了研究.研究结果表明：碰撞产生的等离子体密度数值计算结果与粒子模拟结果基本一致,背景气压在0.01 Pa—0.05 Pa时,碰撞产生的等离子体密度在4—12×10⁹cm^-3,即便在考虑电子离子复合的情况下,数值计算结果与粒子模拟结果依然符合得很好.另外,粒子模拟结果表明：随着气压的增加,等离子体密度呈现先增大再减小然后又逐渐增大的过程, 关键词： 相对论电子束 等离子体 数值计算 粒子模拟     

Generation of high-current electron beams by a hollow cathode with a ferroelectric plasma source

This paper presents results and analysis of an experimental investigation of the operation of a hollow cathode (HC) with an incorporated ferroelectric plasma source (FPS). It was shown that the use of FPS based on a BaTi solid solution allows one to ignite and to sustain a 10²-10³ A HC discharge with duration of 10^-3-10^-5 s at background pressure of 5 x 10^-3 Pa while keeping the HC design with small dimensions. It was found that the development of the HC discharge is accompanied by formation at the surface of the FPS of dense plasma which serves as a powerful (hundreds of kW) pulsed source of current carrying electrons. Parameters of the HC plasma (radial distribution of the plasma density and temperature and plasma potential) for different discharge current amplitudes and two types of FPS are presented. Application of the FPS as an electron source in a diode under an accelerating pulse 300 kV and pulse duration 400 ns showed that the latter operates in a plasma pre-filled mode with a current amplitude up to 1.6 kA. Parameters of the diode and electron beam for different experimental conditions are presented and discussed.Received: 10 April 2003, Published online: 12 August 2003PACS: 52.50.Dg Plasma sources - 29.25.Bx Electron sources - 52.25.Tx Emission, absorption, and scattering of particles     

基于激光等离子体加速的自由电子激光研究新进展

激光等离子体加速器能够在cm尺度内产生GeV量级的高品质电子束,为研制台式化自由电子激光提供驱动源。但是受限于激光等离子体加速中的难点和现有技术发展,电子束的品质难以达到自由电子激光的需求,尤其在稳定性、发散角和能散等方面,阻碍了台式化自由电子激光的研制。介绍了基于激光等离子体加速器的自由电子激光的最新进展,整理了目前高增益自由电子激光实验过程中存在的主要挑战和对应的解决方案与实验进展,并展望未来的发展方向。最近的研究结果证明,通过控制和优化激光等离子体加速器的注入和加速过程产生的高品质电子束可以在指数增益区域实现自发辐射放大,产生高增益的辐射,这也推动基于激光等离子体加速器的自由电子激光研究进入了一个新的阶段。     

Nonclassical transport in a nonequilibrium laser plasma

The onset of a nonequilibrium distribution function in a plasma produced by laser radiation at fluxes I - 10¹⁴ W/cm² is considered. The model employed takes consistent account of the nonlocality of the electron distribution at large density and temperature gradients, the demaxwellizing effect of the external hf field of the laser, and the nondiffusion of the transport in the high-energy part of the electron-distribution spectrum. Numerical solution of the corresponding kinetic equations shows that establishment of a nonequilibrium electron distribution in the corona suppresses the heat transport substantially. Good agreement is obtained between the kinetic value of the heat flux and the phenomenological value needed to reconcile the hydrodynamicsimulation results with the experimental data.Quantum Radiophysics Division, Lebedev Physics Institute. Translated from Preprint No. 179 of the Ledebev Physics Institute, Academy of Sciences of the USSR, Moscow, 1989.