排序方式: 共有46条查询结果,搜索用时 15 毫秒
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A simple collisional radio frequency (rf) sheath fluid model, which is not restricted by the ratio of rf frequency to ion plasma frequency (β = ωrf/ωpi), was established and solved numerically. In the ion balance equation, the effect of the collision on the ion and the ion velocity is assumed to be a direct ratio to ion velocity. The ion energy distributions (IEDs) calculated in the model in comparison with the experimental data [M. A. Sobolewski, J. K. Olthoff, and Y. C. Wang, J. Appl. Phys. 85, 3966 (1999)], proved the validity of the model. And the effect of the collision on the sheath characteristic was obtained and discussed. This paper demonstrates that the collision frequency is another crucial parameter as well as the ratio β to determine the rf sheath characteristics and the shape of IEDs. 相似文献
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Acoustic breathing modes of dusty plasmas have been investigated in a cylindrical system with an axial symmetry. The linear wave solution and a “dispersion” relation were derived.It was found that in an infinite area, the mode is reduced to a “classical” dust acoustic wave in the region away from the center. If the dusty plasma is confined in a finite region, however, the breathing (or heart-beating) behavior would be found as observed in many experiments. 相似文献
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Mingyang WU 《等离子体科学和技术》2022,24(5):55002
Helicon wave plasma sources have the well-known advantages of high efficiency and high plasma density, with broad applications in many areas. The crucial mechanism lies with mode transitions, which has been an outstanding issue for years. We have built a fluid simulation model and further developed the Peking University Helicon Discharge code. The mode transitions, also known as density jumps, of a single-loop antenna discharge are reproduced in simulations for the first time. It is found that large-amplitude standing helicon waves (SHWs) are responsible for the mode transitions, similar to those of a resonant cavity for laser generation. This paper intends to give a complete and quantitative SHW resonance theory to explain the relationship of the mode transitions and the SHWs. The SHW resonance theory reasonably explains several key questions in helicon plasmas, such as mode transition and efficient power absorption, and helps to improve future plasma generation methods. 相似文献
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Min WANG 《等离子体科学和技术》2022,24(1):15101
Impurity seeding has been found effective for divertor detachment operations and the seeding location plays a key role in this process. In this work, we use the fluid code SOLPS-ITER to study the influence of seeding locations on divertor and scrape-off layer (D-SOL) plasmas in Experimental Advanced Superconducting Tokamak (EAST) with neon seeding. Simulation results indicate that the neon is a highly effective impurity in mitigating the heat flux and electron temperature peaks on the target of the divertor and achieving the partial detachment on both inner and outer targets. Further, by comparing results of the seeding at the private-flux region (PFR) plate (called 'TP' location) and the outer target (called 'XP' location), we find that the impurity density and power radiation for TP case are higher in core and upstream regions and lower in the divertor region than that for seeding at the XP, and the difference becomes more and more obvious as the seeding rate increases. It clearly demonstrates that the seeding at the XP location is more appropriate than at the TP location, especially in high seeding rate conditions. 相似文献