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在Debye-Hückel屏蔽近似下,基于相对论Dirac-Fock方法,发展了包括等离子体屏蔽效应的自洽场计算程序.使用该程序研究了等离子体屏蔽效应对类氢离子能级结构和辐射跃迁性质的影响.结果表明,当原子处于等离子体环境中,所有束缚态能级向连续态移动, 移动量随着屏蔽长度的减小而增大.振子强度随屏蔽长度的变化也表现出了相同的规律.进一步分析了相对论效应和等离子体屏蔽效应的耦合,发现对于中Z元素,相对论效应和等离子体屏蔽效应存在较强的耦合.讨论了等离子体屏蔽效应对原子精细结构能级的影响.计算发现,由于等离子体屏蔽效应,原子的能级次序发生了变化,κ简并被消除.
关键词:
等离子体屏蔽
Debye-Hückel 模型
能级结构
跃迁概率 相似文献
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本文采用多组态Dirac-Hartree-Fock方法研究了温稠密等离子体环境中Al12+离子的光电离过程. 等离子体效应采用SM屏蔽势来模拟(Stanton和Murillo在2015年提出). 计算中固定标度温度1.3eV,在强耦合等离子体环境下,研究了等离子体密度对能级,连续态波函数以及光电离截面的影响. 通过与相同等离子体条件下的Debye-Hückel模型势计算的光电离截面对比,发现两种模型对应的结果中未同时出现势形共振峰,这是由于本文采用的屏蔽模型包含等离子体简并、有限温度对动能的梯度修正和量子交换关联效应,对光电离截面的大小和共振结构具有显著影响. 相似文献
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本文将等离子体核聚变反应截面研究中利用等离子体环境涨落进行修正了的Debye-Hückel屏蔽势推广到计算等离子体中辐射离子束缚态的能级结构. 通过Tsallis参数q的变化,在等离子体辐射离子束缚态能级结构的计算中加入等离子体参数涨落的平均效应,即,等离子体动力学. 具体给出了利用修正的Debye-Hückel屏蔽势对类氦铝束缚态能级结构的计算结果. 结果表明基于这种修正的屏蔽势,自由电子的极化分布具有和线性Debye-Hückel屏蔽势不同的结构. 这种通过等离子体涨落分布对屏蔽势函数进
关键词:
等离子体中的原子结构
等离子体环境涨落
修正了的Debye-Hückel屏蔽势 相似文献
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介绍了HCSB TBM屏蔽块的初步设计,根据RCC-MR相关标准,在4种典型工况下对TBM屏蔽块的结构性能进行了分析和校核。计算结果表明:所有工况下的整体形变都较小,一次应力和二次应力均满足RCC-MR标准。 相似文献
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介绍了HCSB TBM 屏蔽块的初步设计,根据RCC-MR 相关标准,在4 种典型工况下对TBM 屏蔽块的结构性能进行了分析和校核。计算结果表明:所有工况下的整体形变都较小,一次应力和二次应力均满足 RCC-MR 标准。 相似文献
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在Debye屏蔽近似下,通过求解Schrödinger方程,计算了处于等离子体中的类氢离子的束缚态能量本征值与本征函数. 研究了氢原子和类氢Fe25+离子的n l ( n =1-4, l = 0-3)态能级随Debye 屏蔽长度λ的变化规律. 进一步,分析了等离子体屏蔽效应随主量子数n及角量子数l的变化规律, 发现对于给定的l, 等离子体屏蔽效应随主量子数n的增加而增大;对于给定的n,等离子体屏蔽效应随角量子数l 的增大而减小. 最后,我们分析了等离子体环境中类氢等电子序列离子的能级和波函数随屏蔽参数λ的变化规律,发现随着原子序数增大,等离子体屏蔽效应的影响逐渐变小. 相似文献
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本文通过非微扰求解薛定谔方程, 研究了强磁场磁化的等离子体环境中的原子能级结构和辐射动力学过程. 在较宽的磁场强度范围和等离子体屏蔽参数范围内, 给出了氢原子基态以及低激发态的能级、辐射跃迁能量和振子强度等重要的原子参数, 定量地描述了强磁场和等离子体屏蔽共同作用的综合效应. 相关的结果有助于增进对极端环境下原子光谱结构的认识, 在等离子体光谱诊断和天文光谱观测方面有一定的借鉴意义.
关键词:
强磁场
CWDVR谱方法
能级结构
振子强度 相似文献
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In this article, a structure that employs a Faraday shield between the Shoji antenna and the dielectric tube, which aims to reduce the dielectric wall sputtering, is investigated for the helicon wave plasma (HWP) sources. Faraday shield is usually used between the antenna and the reaction chamber to reduce the radiation from the high electromagnetic field generation, as well as to prevent the sputtering of the antenna material from polluting the reaction chamber during the discharge. Here, the influence of the Faraday shield on the longitudinal and radial electric field of the antenna is analysed through COMSOL MultiphysicsTM. Significant attenuations of both the longitudinal and radial fields are observed in the presence of the shield. In addition, by comparing the electric field distribution under two different shielding parameters, it is found that the shielding effects are not the same. Therefore, a detailed study of two kinds of design (pitch and gap) for the shield was carried out. The results show that the pitch has a little impact on the overall shielding effect when the gap is unaltered. The best shielding performance appears when we set the pitch at T of 8 and 10. In addition, the shielding effect also becomes worse as the gap increases while the pitch remains unchanged. A relatively good shielding effect can be produced by setting the gap to the value of 4–8 mm (a gap/pitch ratio of 2/15–4/15). This work provides a theoretical basis for designing a Faraday shield structure between the antenna and the dielectric tube, which is helpful to realize stable and controllable HWP discharges. 相似文献
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Sato Y. Sawaya K. Adachi S. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1988,16(5):574-580
The characteristics of a half-turn loop antenna having a Faraday shield (used for ion-cyclotron RF plasma heating) have been systematically investigated. The main interest is to clarify the Faraday shield effects on the near-zone electric field distribution. It has been confirmed that, in the presence of the Faraday shield, undesirable field components are sufficiently suppressed, and the heating component E y, which otherwise is strongly localized as an end effect, has been found to be distributed uniformly along the antenna in the case of a short electric length. It is found that the shielding strips should be uniformly distributed over the entire region around the half-turn loop antenna 相似文献
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Kwon M. Thomas C.E. Jr. Hoffman D.J. Shepard T.D. Rettig C.L. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1990,18(2):184-189
Compact loop antennas are being applied to several fusion experiments, including DIII-D, the Advanced Toroidal Facility, Tore Supra, and the Tokamak Fusion Test Reactor. Although individual configurations vary, all of these antennas generally comprise a current strap in a recessed box and a Faraday shield. The coupling characteristics of cavity antennas that have current straps with the previously evaluated cross-sectional shapes are tested with several Faraday shields. The coupling is purely a measure of the magnetic flux linkage at relevant ion-cyclotron resonance heating (ICRH) frequencies and does not include plasma spectral effects. Impedances and relative fields are measured for various combinations of the current strap and Faraday shield. The experiments show that the fractional reduction in the magnetic flux linkage to the plasma resulting from the addition of any particular Faraday shield is virtually independent of the shape of the current strap. This is true in spite of the fact that the same mechanism which is responsible for the reduction in flux is also responsible for a significant redistribution of the antenna current on the current strap. Thus the process of optimizing antennas is reduced to that of separately optimizing the current strap and Faraday shield 相似文献
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I. D. Tokman A. V. Shvetsov 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,72(1):97-104
The interrelation between the Faraday and the inverse Faraday
effects when the magneto-dipole interaction of a sample with an
electromagnetic wave is essential has been phenomenologically
investigated. This investigation was carried out in the spirit of
well-known Pitaevsky’s approach. The terahertz inverse Faraday effect
in single molecule magnets has been theoretically studied, the
conditions favorable for observing this effect have been
formulated. 相似文献
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In this study, we investigate Faraday rotation of electromagnetic waves that are anomalously transmitted through an over‐dense magnetized plasma layer. Here, magnetized plasma indicates that the plasma layer is immersed in a uniform magnetic field. Firstly, normally opaque over‐dense magnetized plasma is shown to be transparent to obliquely incident electromagnetic waves. This high transparency can be achieved by providing conditions for resonant excitations of plasmonic modes. The resonant characteristics of the transmission coefficient of the considered structure are determined and discussed. The conditions under which the magnetized plasma behaves as a complete reflector are also obtained. Faraday rotation is shown to be enhanced under high transparency conditions. The reflected wave also exhibits Faraday rotation and is enhanced under total reflection conditions. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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A resonant cavity antenna designed to be suitable for ion cyclotron heating in a tokamak has been bench tested. This antenna is a "discrete element" circuit designed to launch the fast magnetosonic wave in a magnetized plasma. The resonant autotransformer design allows matching to the transmission-line impedance. The tuning and matching properties of this antenna have been compared with a simple computer model. The effective transmission of various Faraday shields has been determined by measuring the change in Q of the antenna system with and without the shield. The test results show that the antenna behaves as predicted by a simple computer model and that coolable Faraday shields with high RF transmission can be designed. 相似文献
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An analytic expression is given for the inverse Faraday effect, i.e., for the magnetization occuring in a transparent medium exposed to a circularly polarized high-frequency electromagnetic wave. Using a microscopic approach based on the Drude approximation of a free-electron gas, the magnetization of the medium due to the inverse Faraday effect is identified as the result of microscopic solenoidal currents generated by the electromagnetic wave. In contrast to the better known phenomenological derivation, this microscopic treatment provides important information on the frequency dependence of the inverse Faraday effect. 相似文献