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1.
A theoretical and computational model is presented to study the ionization of the argon electron cyclotron resonance(ECR)microwave discharge using a quasi-three-dimensional electromagnetic particle-in- cell plus Monte Carlo collision method.The interaction between the charged particles and microwave fields are described by the electromagnetic mode of particle-in-cell method.The collision processes are treated with Monte Carlo method.The simulation code is the original work.The results of the particle simulation for the ECR discharge of argon gas which include the microscopic features of charged particles and the electromagnetic characteristics of the ECR discharge plasma,and also the transient phenomena have been presented. 相似文献
2.
Aghamir F. M. Goodarzi P. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》2010,38(1):10-18
3.
介绍了离子回旋波加热领域研究进展,具体分析了快波少子加热模式转换情况以及影响模式转换分量大小和位置的因素。通过控制波的频率及少子浓度,使得波能够顺利传播到托卡马克等离子体的离子混合共振与截止的区域附近,并转换为离子Bernstein波而被等离子体有效吸收,因而能够改善加热效果。 相似文献
4.
LaRose Alan R. Tang Ting-wei Caron Paul R. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1974,2(4):291-296
An experiment is described in which an electromagnetic wave (extraordinary mode) is propagated across a magnetized plasma and second harmonic generation is detected. The generation of the plasma and the second harmonic wave is associated with resonant conditions of electron cyclotron resonance and upper hybrid resonance. By adjusting the intensity of axial magnetic field, the second harmonic generation can be made solely due to the electron cyclotron resonance, the upper hybrid resonance or both. The experiment is qualitatively in agreement with previous similar experiments and can be explained in terms of the spatial variations of the magnetic field intensity and the electron number density. A technique for diagnosing peak number density is developed from the observed second harmonic power characteristics. 相似文献
5.
F. Consoli S. Barbarino L. Celona G. Ciavola S. Gammino D. Mascali 《辐射效应与固体损伤》2013,168(10-12):467-475
Both theoretical and numerical electromagnetic analyses about the modes inside the cylindrical cavity of superconducting electron cyclotron resonance ion source (SERSE) have been performed. Modes close to 14, 18 and 28 GHz frequencies, usually employed in SERSE operating conditions, have been calculated in vacuum and when the chamber is filled with a uniform non-collisional plasma at different electron densities. To consider the holes present in the chamber flanges, a numerical approach has been used, by means of the HFSSTM electromagnetic simulator, for the first mode in the cavity. Modes in a plasma-filled cylindrical cavity with holed bases have full width half maximum bandwidths larger with regard to the closed cavity in vacuum, and it leads to an increased mode frequency overlap. A monochromatic electromagnetic wave feeding this cavity can, in principle, excite different modes. Further investigations about the coupling between the SERSE cavity and its feeding waveguides have to be performed. 相似文献
6.
Jaeger EF Berry LA Myra JR Batchelor DB D'Azevedo E Bonoli PT Phillips CK Smithe DN D'Ippolito DA Carter MD Dumont RJ Wright JC Harvey RW 《Physical review letters》2003,90(19):195001
A two-dimensional integral full-wave model is used to calculate poloidal forces driven by mode conversion in tokamak plasmas. In the presence of a poloidal magnetic field, mode conversion near the ion-ion hybrid resonance is dominated by a transition from the fast magnetosonic wave to the slow ion cyclotron wave. The poloidal field generates strong variations in the parallel wave spectrum that cause wave damping in a narrow layer near the mode conversion surface. The resulting poloidal forces in this layer drive sheared poloidal flows comparable to those in direct launch ion Bernstein wave experiments. 相似文献
7.
The experimental conditions that facilitate the excitation of parametric decay instabilities upon the electron cyclotron resonance heating of a plasma at the second harmonic extraordinary wave in tokamaks and stellarators and, as a result, make anomalous absorption of microwave power possible have been analyzed. It has been shown that, in the case of a nonmonotonic radial profile of the plasma density, when the beam of electron cyclotron waves passes near the equatorial plane of a toroidal device, the parametric excitation of electron Bernstein waves, as well as the generation of ion Bernstein waves propagating from the parametric decay region to the nearest ion cyclotron harmonic, where they efficiently interact with ions, is possible. The proposed theoretical model can explain the anomalous generation of accelerated ions observed upon electron cyclotron heating in small and moderate toroidal facilities. 相似文献
8.
We have analyzed experimental conditions for the excitation of absolute parametric decay instabilities accompanying the electron
cyclotron resonance heating (ECRH) of plasma at the second harmonic of resonance in tokamaks. It has been shown that, in the
case of a nonmonotonic radial profile of the plasma density, when a heating beam passes near the equatorial plane of a tokamak,
the parametric excitation of resonances of ion Bernstein waves accompanied by the generation of the backscattered microwave
radiation can occur. The threshold of absolute instability thus developed is determined by the dissipation of an ion Bernstein
wave and can be exceeded in current experiments on the ECRH of a plasma in tokamaks. 相似文献
9.
Properties of several plasma waves in a wavenumber space are investigated in a hot magnetized plasma. The properties are applied to investigate ray trajectories of radiated electromagnetic waves to an inhomogeneous plasma and mode conversion of the extraordinary mode into electrostatic cyclotron harmonic waves at the upper hybrid frequency layer. The wave fronts of the mode-converted cyclotron harmonie wave from the extraordinary wave are made clear. Furthermore, ray trajectories of radiated cyclotron harmonic waves and the mode-converted extraordinary mode are obtained. 相似文献
10.
考虑束-离子通道边界上等离子体电子可能发生的扰动,导出了TM模本征方程的理论式.通过对理论结果的数值模拟计算,在阶跃边界情况下将束-离子通道与一般介质波导的电磁关系进行了比较,发现束-离子通道可以通过改变等离子体频率来控制其工作模式.分析对照扰动电荷边界与阶跃边界对束-离子通道电磁模式的影响,观察到在扰动电荷边界情况下,束-离子通道在低频区域(ω<ωp,ωp为等离子体频率)内截止频率显著提高,并在高频区域(ω>ωp)内出现了新的电磁模式.研究结果对离子通道激光(ICL)和离子通道电子回旋脉塞(ICECM)的设计提供重要的理论依据.
关键词:
束-离子通道
阶跃边界
扰动电荷边界
电磁模式 相似文献
11.
一、引 言 在一些较大型的托卡马克装置上的研究业已表明,应用外激发离子伯恩斯坦波(IBW)对托卡马克等离子体进行辅助加热是一种极具有竞争力的方法。然而,对在托卡马克位形的等离于体中,IBW的激发、传播等一些基本过程,仍需做进一步的实验研究。我们利用小型装置的低温、低密度特点,采用高空间分辨的射频(RF)电探针作为IBW的主要探测 相似文献
12.
13.
徐茵 《核聚变与等离子体物理》1989,9(2):78-85,120
本文对托卡马克位形,用动力理论研究了非均匀热等离子体的ICRF快波模转换及有关的阻尼机制。结果表明,对于多种离子成分的等离子体,在离子-离子混杂共振层和二次谐波回旋共振层附近,存在快波和离子伯恩斯坦波(IBW)之间的模转换;模转换层附近的色散关系与k_(?),离子种类浓度以及等离子体密度有明显的相关性。适当选择这些参数可大大改善快波能量的吸收和吸收的局域性。而在一种离子成分的等离子体中、无模转换过程发生。 相似文献
14.
The steady state nonlinear propagation of an intense, circularly polarized electromagnetic beam in an inhomogeneous magnetized plasma has been investigated in paraxial approximation. The laser induces a large oscillatory velocity on electrons, raising their mass and lowering the plasma frequency. Further, rising due to cyclotron resonance effect. The propagation of the electromagnetic waves in magnetized plasma in both the extraordinary and ordinary mode is analyzed. The nonlinearity in dielectric function is considered in presence of external magnetic field due to saturation effects for arbitrary large intensity, which leads to focusing/defocusing of the beam. The focusing effect along with magnetic field helps in the process of anomalous penetration of the beam by enhancing the depletion of the plasma from the axial region. The penetration increases with the incident beam power up to some critical value beyond which it rises abruptly when all electrons have been driven out of the axis. The cyclotron resonance effect awfully supports the laser beam to propagate inside the overdense plasma region. Numerical computations are performed for typical parameters of relativistic laser–plasma interaction applicable for underdense and overdense plasma. 相似文献
15.
Renlong Zhou Hongjian Li Bingju Zhou Lingxi Wu Xiaojuan Liu Yongyi Gao 《Solid State Communications》2009,149(15-16):657-661
We theoretically and numerically studied the transmission of light through a subwavelength-perforated metal film in the presence of an external magnetic field. The perforated metal films are found to exhibit a magnetoinduced light transparency due to cyclotron resonance. The localized waveguide surface plasmon (SP) resonance mode and periodicity-structure-factor-induced SP resonance mode are discussed by application of a static magnetic field. The field distributions are localized separately on the left and right metal-air surfaces for structure-factor-induced resonance mode. And for localized cavities resonance mode, standing electromagnetic fields can also be entirely localized inside the nanohole region. 相似文献
16.
The experimental conditions have been analyzed for a significant reduction of the threshold of the reflective parametric decay
instabilities under electron cyclotron resonance heating (ECRH) of a plasma in magnetic devices in the absence of the upper
hybrid resonance for the pump wave. The role of the nonmonotonic profile of the plasma density near the O point of the magnetic
island, which allows for the localization of ion Bernstein waves in the direction of the density gradient and the suppression
of convective losses from the decay region has been discussed. It has been shown that the threshold of the instability of
the induced backscattering near the local maximum of the density profile is decreased by four orders of magnitude and is easily
exceeded in present-day ECRH experiments at a power of several hundred kilowatts. 相似文献
17.
18.
The dispersion properties of slow electromagnetic surface waves propagating across a constant external magnetic field and
along a plane plasma-metal interface at harmonics of the ion cyclotron frequency are studied. The motion of the plasma particles
is described by a Vlasov-Boltzmann kinetic equation. The effects of the plasma size, the dielectric permittivity of the transition
region between the plasma and metal, and the magnitude of the constant external magnetic field on the dispersion characteristics
of ion surface cyclotron waves are studied.
Zh. Tekh. Fiz. 69, 83–89 (October 1999) 相似文献
19.
Parks GK Lee E Lin N Mozer F Wilber M Dandouras I Rème H Lucek E Fazakerley A Goldstein M Gurgiolo C Canu P Cornilleau-Wehrlin N Décréau P 《Physical review letters》2007,98(26):265001
Solitary nonlinear (deltaB/B>1) electromagnetic pulses have been detected in Earth's geomagnetic tail accompanying plasmas flowing at super-Alfvénic speeds. The pulses in the current sheet had durations of approximately 5 s, were left-hand circularly polarized, and had phase speeds of approximately the Alfvén speed in the plasma frame. These pulses were associated with a field-aligned current J(parallel) and observed in low density (approximately 0.3 cm(-3)), high temperature (T(e) approximately T(i) approximately 3x10(7) K), and beta approximately 10 plasma that included electron and ion beams streaming along B. The wave activity was enhanced from below the ion cyclotron frequency to electron cyclotron and upper hybrid frequencies. The detailed properties suggest the pulses are nonlinearly steepened ion cyclotron or Alfvén waves. 相似文献
20.
A right-hand circularly polarized (RHCP) electron cyclotron wave is launched along the axis of a steady-state magnetically confined plasma column. Detailed measurements of the spatial variation of electron temperature, density, plasma potential, and wave amplitude about the resonance zone are presented. In particular, data are presented where the temperature increase due to electron cyclotron resonance heating (ECRH) is strongly localized near the resonance position. A numerical wave heating model has been developed for electrons in a magnetic mirror and is found to be in qualitative agreement with observations. 相似文献