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。     

激光诱发SiH4＋CH4等离子体的发射光谱

本工作采用光学发射谱方法测量了ＴＥＡ ＣＯ２脉冲激光辐射ＳｉＨ４＋ＣＨ４系统产生的等离子体反应过程中的发射谱特性，探测到了Ｓｉ，Ｓｉ＾＋，Ｓｉ＾２＋，Ｃ，Ｃ＾＋，Ｃ＾２＋，ＣＨ，ＳｉＨ，ＳｉＨ＾＋，Ｓｉ２和Ｈ的特征辐射，研究了含Ｃ，Ｓｉ碎片粒子光谱随实验条件的变化规律，并讨论了反应条件对ＯＥＳ的影响。     

He（2^3S）与N2O（X）Penning电离中的N2O^＋（A^2Σ^＋）生成速率及相…

在分子束条件下测量了Ｈｅ（２＾３Ｓ）＋Ｎ２Ｏ（Ｘ）→Ｎ２Ｏ＾＋（Ａ＾２Σ＾＋）＋Ｈｅ（＾１Ｓｏ）＋ｅ＾－反应的Ｐｅｎｎｉｎｇ电离光学光谱，求得了Ｎ２Ｏ＾＋（Ａ＾２Σ＾＋）态的初生态相对振动布居。以Ｈｅ（２＾３Ｓ）＋Ｎ２（Ｘ）→Ｎ＾＋２（Ｂ＾２Σ＾＋ｕ）＋Ｈｅ（＾１Ｓｏ）＋ｅ＾－为参考反应，测量了Ｈｅ（２＾３Ｓ）＋ＢＮ２Ｏ＾＋（Ａ＾２Σ＾＋）＋Ｈｅ（＾１Ｓｏ）＋ｅ＾－反应的速率常数ＫＮ２Ｏ＾＋（Ａ）     

束—气条件下He（2^3S）＋CH2Cl2碰撞传能反应的动力学研究

本文在束－气条件下研究了亚稳态原子Ｈｅ（２＾３Ｓ）与ＣＨ２Ｃｌ２间的传能反应，测得了由该反应产生的ＣＨ（Ａ＾２△－Ｘ＾２П），ＣＨ（Ｂ＾２∑＾－Ｘ＾２П）ＣＨ（Ｃ＾２∑＾＋－Ｘ＾２П）和Ｈ原子（Ｂａｌｍｅｒ系）的化学发光光谱。通过对ＣＨ（Ａ，Ｂ）的光谱进行计算机模拟，推测出初手的ＣＨ（Ａ＾２△，ｖ＾１＝０－２）态振动分布为Ｎｏ：Ｎ１：Ｎ２＝１００：４０±５：１９±２，ＣＨ（Ａ＾２△，ｖ＾１＝０－０     

火焰原子吸收法间接测定植物中的硫

根据植物中的硫消化后，消化液中的ＳＯ＾２－４与ＢａＣｒＯ４悬浊液反应释放出ＣｆＯ＾２－４，用火焰原子吸收法间接测定ＳＯ＾２－４。本文研究了影响试样消化液中ＳＯ＾２－４定量测定的各种条件，通过加入一定的量的钙，解决大量共存ＰＯ＾３－４的干扰。与电感耦合等离子体发射光谱法进行了结果对照，基本一致。     

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。     

La2O3—BaO系复氧化物的现场拉曼光谱研究

对于Ｌａ０．２Ｂａ０．８－ｘＣａｘ（Ｏ，ＣＯ３）其中ｘ＝０．０、０．２、０．４、０．６氧化物在９７３Ｋ及甲烷氧化偶联（ＯＣＭ）条件下，无Ｃａ＾２＋的样品可用表面ＢａＣＯ３和（ＬａＯ）２ＣＯ３的Ｒａｍａｎ谱及８１０ｃｍ＾－１附近的Ｏ２＾２－特征峰来表征；含Ｃａ＾２＋的样品，则表现了混合碳酸盐（Ｃａ，Ｂａ）ＣＯ３的特征，还有位于１１３５ｃｍ＾－１（ｗ）和８１０ｃｍ＾－１（ｗ）的Ｏ２＾－、Ｏ２＾２－瞬时     

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。     

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。     

ICP—AES法直接测定高纯Eu2O3中14种稀土元素

建立了ＩＰＣ－ＡＥＳ测定高纯Ｅｕ２Ｏ３中１４种稀土元素的方法，用正交设计法优化仪器测量条件，实验了基体Ｅｕ２Ｏ３对被测元素的干扰和对方法测定下限的影响。１４个稀土元素的测定下限为：Ｙｂ２Ｏ３０．５μｇ．ｇ＾－１，Ｙ２Ｏ３１μｇ．ｇ＾－１，Ｄｙ２Ｏ３，Ｈｏ２Ｏ３，Ｔｍ２Ｏ３和Ｎｄ２Ｏ３５μｇ．ｇ＾－１、Ｇｄ２Ｏ３、Ｓｍ２Ｏ３、Ｅｒ２Ｏ３、Ｃｅ２Ｏ３、Ｐｒ６Ｏ１１和Ｌａ２Ｏ３１０μｇ．ｇ＾－１，Ｌｕ２     

Parameters of the beam plasma formed by a forevacuum plasma source of a ribbon beam in zero-field transportation system

We have studied the generation of the beam plasma formed by a forevacuum plasma source of a ribbon electron beam in the conditions of its transportation without an accompanying magnetic field. The ignition conditions in the beam transportation region of the beam–plasma discharge producing a plasma formation of the plasma sheet type with a plasma concentration of ~10¹⁶ m^–3 and an electron temperature of 1–2.5 eV have been determined. The attained values of parameters and the sizes of the plasma formation make it possible to use it in technologies of the surface modification of planar extended articles.     

Flow Characteristics in the Exhaust of a Pulsed Megawatt Gas Fed Arc

The transient flow generated by a pulsed, megawatt-level, gas-fed arc with an applied magnetic nozzle has been examined with a new design piezoelectric pressure transducer. Sensor thermal conduction and accelerations have been examined and eliminated in the 500?sec period of plasma flow. Existence of a large magnitude cold gas pressure front of 20?sec duration has been reconfirmed and its relationship to the following plasma flow of about 200?sec duration has been examined for the first time. At a point 30 cm from the arc source, initially near vacuum conditions (typically with an arc current of 11.2 kA and 1 tesla applied magnetic field), a pressure pulse of unionized gas with a magnitude of 104 N/m2 is followed by plasma flows with nearly constant impact pressure of 103 N/m2. Pressure and number density in this plasma region are seen to decrease with applied magnetic field strength. With electron density derived from Thomson scattering measurements (1020 m-3) plasma flow velocities on the order of 5 × 104 m/sec are calculated.     

A One‐Dimensional Particle‐in‐Cell Model of Plasma Build‐Up in Vacuum Arcs

Understanding the mechanism of plasma build‐up in vacuum arcs is essential in many fields of physics. A one‐dimensional particle‐in‐cell computer simulation model is presented, which models the plasma developing from a field emitter tip under electrical breakdown conditions, taking into account the relevant physical phenomena. As a starting point, only an external electric field and an initial enhancement factor of the tip are assumed. General requirements for plasma formation have been identified and formulated in terms of the initial local field and a critical neutral density. The dependence of plasma build‐up on tip melting current, the evaporation rate of neutrals and external circuit time constant has been investigated for copper and simulations imply that arcing involves melting currents around 0.5–1 A/μm², evaporation of neutrals to electron field emission ratios in the regime 0.01 – 0.05, plasma build‐up timescales in the order of ～ 1 – 10 ns and two different regimes depending on initial conditions, one producing an arc plasma, the other one not. Also the influence of the initial field enhancement factor and the external electric field required for ignition has been explored, and results are consistent with the experimentally measured local field value of ～ 10 GV/m for copper (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Parametric study of plasma active medium and gain saturation region in a Ne-like soft X-ray laser

Plasmas created by the interaction of high power optical laser with a target surface can be used as a source of soft X-ray lasers. Plasma and pump laser characteristics play significant role in achieving high gain coefficient for such plasma based on soft X-ray lasers. In the present work, the plasma active medium parameters for germanium element at a wavelength of 19.6 nm irradiated by a double-pulse pump laser have been studied using MED103 hydrodynamic code. For this purpose, first, the effects of laser intensity, pulse width and delay time of two pulses on the gain coefficient have been investigated and the optimum conditions for the maximum gain extent of Ne-like germanium soft X-ray laser are obtained. Then, in order to calculate the intensity of such high gain lasers in which Linford equation is invalid, we have adopted the general formula of amplified spontaneous emission intensity, which is valid in all range of intensities even at much higher intensities than saturation intensity. Finally, the soft X-ray laser intensities in the saturated areas for different plasma lengths have been calculated. The results show that the output of soft X-ray laser intensity with 294 cm⁻¹ gain coefficient can reach to about several times saturated intensity by applying a 1–2 mm plasma length as the active medium.     

Two-dimensional modeling and simulation for dynamic sheathexpansion during plasma immersion ion implantation

A pseudo two-dimensional (2-D) analytical model and a 2-D plasma simulator PDP2 code have been utilized to characterize ion-matrix sheath and dynamic sheath expansion during the plasma immersion ion implantation process. The pseudo 2-D model is very simple by involving two geometry factors and yields an acceptable accuracy under the current process conditions. Good agreement between the pseudo 2-D model and PDP2 simulation was observed     

Bound states and resonance states of the plasma-embedded tdμ and ddμ molecular ions

We have investigated the bound states and resonance states of plasma-embedded tdμ and ddμ molecular ions using accurate correlated basis functions. The plasma effect has been taken care of by considering the Debye shielding approach of plasma modeling which admits a variety of plasma conditions. The density of resonance states are calculated using the stabilization method. The ground and excited states energies, and the S-wave resonance energies of tdμ and ddμ molecular ions immersed in plasmas are reported for various shielding parameters, along with the 1S and 2S threshold energies of the tμ and dμ atoms.     

Lowest lying <Superscript>1</Superscript>D<Superscript>e</Superscript> resonance of H<Superscript>-</Superscript> in Debye plasma

Electron-hydrogen scattering has been investigated in Debye plasma environment employing the close-coupling approximation. Two models, viz., 6-state CCA and 9-state CCA have been used. Plasma screening has been taken into account via Debye-Hückel model potential. The lowest lying ¹D^e^1{\rm D}^{{\rm e}} auto-detaching resonance of the hydrogen negative ion has been successfully predicted for various plasma conditions. The resonant state changes to shape resonance for Debye scattering lengths less than a critical value.     

Spectra of heliumlike carbon,aluminium and argon under strongly coupled plasma

Spectral line positions for the highly stripped helium like carbon, aluminium and argon embedded in intense plasma environments have been calculated theoretically to compare with the existing data available from laser plasma experiments. The changes in the ionization potentials for such ions have been determined and the excitation energies, oscillator strengths and transition probabilities for the transitions 1s^{2 1}S → 1snp ¹P (n=2-5) have been evaluated for the diagnostic determination of such plasmas. The ion sphere (IS) model was used for estimating the effect of strongly coupled plasma on the ions within the non-relativistic as well as the relativistic framework. Time dependent perturbation theory has been applied for obtaining the linear response properties of the ions in the non-relativistic approximation. The effects of the plasma environment on such properties of the ions under the Debye screening model with suitable cut off radii have also been considered for comparing the data with those obtained from the IS model of the plasma.     

Simulation of the ignition transient in RF inductively-coupled plasma torches

The paper deals with the time-dependent numerical simulation of inductively-coupled plasma torches during the ignition transient, which is induced by a graphite rod and leads to the final, self-sustaining plasma condition. The study has been performed by using a 2D time-dependent fluid-magnetic code based on the SIMPLER algorithm within the assumptions of laminar flow, local thermodynamic equilibrium conditions and optically thin plasma. The graphite rod has been treated as a real obstacle for the gas and the electron emission due to the thermoionic effect has been suitably taken into account. The advantage of using a time-dependent code in order to select different plasma operating conditions that can lead to stable discharges is pointed out. Results for both argon and air discharges are presented for different torch geometries, RF frequencies and inlet gas configurations (also including the presence of a carrier gas injected along the axis of the torch). Moreover, the final self-sustaining plasma configurations obtained are compared, when available, with results coming from static models, which have been published by other authors. Received 29 December 2000     

Stark broadening in the Sb III spectrum

The shapes of nine doubly ionized antimony (Sb III) spectral lines have been obtained in the laboratory helium plasma at 17 500 K electron temperature and electron density of . Measured line profiles are of a Voigt type. At the mentioned plasma conditions the Stark broadening has been found as the dominant mechanism in the Sb III line shapes formation. Using a deconvolution procedure the Lorentz (Stark) FWHM (Full-Width at Half of the Maximal intensity, W) have been obtained. Our measured Sb III Stark widths are the first data in the literature. The modified version of the linear, low-pressure, pulsed arc was used as a plasma source operated in helium with antimony atoms, as impurities. They were evaporated from the thin antimony layer, deposited on the silver cylindrical plates, located in the homogenous part of the discharge. This plasma source ensures good conditions for the generation of the doubly ionized antimony atoms in the helium plasma due to atomic processes concerning helium metastables.