排序方式: 共有13条查询结果,搜索用时 15 毫秒
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An estimation method of plasma density based on surface plasmons theory for surface-wave plasmas is proposed. The number of standing-wave is obtained directly from the discharge image, and the propagation constant is calculated with the trim size of the apparatus in this method, then plasma density can be determined with the value of 9.1 × 10^17m^-3. Plasma density is measured using a Langmuir probe, the value is 8.1 × 10^17m^-3 which is very close to the predicted value of surface plasmons theory. Numerical simulation is used to check the number of standing-wave by the finite-difference time-domain (FDTD) method also. All results are compatible both of theoretical analysis and experimental measurement. 相似文献
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A numerical simulation of surface wave excitation in a rectangular planar-type plasma source 下载免费PDF全文
The principle of surface wave plasma discharge in a rectangular
cavity is introduced simply based on surface plasmon polariton
theory. The distribution of surface-wave electric field at the
interface of the plasma-dielectric slab is investigated by using the
three-dimensional finite-difference time-domain method (3D-FDTD)
with different slot-antenna structures. And the experimental image
of discharge with a novel slot antenna array and the simulation of
the electric field with this slot antenna array are both displayed.
Combined with the distribution of surface wave excitation and
experimental results, the numerical simulation performed by using
3D-FDTD is shown to be a useful tool in the computer-aided antenna
design for large area planar-type surface-wave plasma sources. 相似文献
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The extraction of negative ions inevitably leads to the destruction of the original plasma state. To understand the effect of extraction on a plasma sheath under a weak magnetic filter field, the time-dependent behavior of H~- ion extraction from a negative ion source has been studied by particle-in-cell simulation in the collisionless limit. The simulation results have shown that the plasma sheath would undergo a transient process, in which there exists an edge electrostatic wave that propagates counterclockwise along the wall with a velocity of 4 mm/ns until it reaches the other side of extraction aperture. The thickness of the plasma sheath and the plasma potential both increase greatly at the final quasi-steady-state. For comparison, the results of extracting positive ions are also given. 相似文献
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论述了离子束作用下固体表面次级电子产生的机制,介绍了特种真空器件中次级电子抑制的各种方法及其优缺点,提出了脉冲离子束作用下靶面次级电子抑制的自偏势法和曲面靶法等设计思路,并在实验上进行了初步验证。实验结果表明,自偏势电压大于80 V后,次级电子得到很好的抑制。在相同束流情况下,曲面靶较平面靶的次级电子产额少。利用实验结果进行估算得到了近似的次级电子产额约为0.67,比文献中的结果(0.58)偏大。对实验中自偏势法抑制反峰电子电流的效果进行了分析和讨论,结果表明:自偏势法不但能够有效抑制离子打靶产生的次级电子,还能抑制由功率源不稳定带来的入射反峰电子流。 相似文献
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The resonant absorption of a plasma surface wave is supposed to be an important and efficient mechanism of power deposition for a surface wave plasma source. In this paper, by using the particle-in-cell method and Monte Carlo simulation, the resonance absorption mechanism is investigated. Simulation results demonstrate the existence of surface wave resonance and show the high efficiency of heating electrons. The positions of resonant points, the resonance width and the spatio-temporal evolution of the resonant electric field are presented, which accord well with the theoretical results. The paper also discusses the effect of pressure on the resonance electric field and the plasma density. 相似文献
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Self-consistent three-dimensional modeling and simulation of large-scale rectangular surface-wave plasma source 下载免费PDF全文
A self-consistent and three-dimensional (3D) model of argon
discharge in a large-scale rectangular surface-wave plasma (SWP)
source is presented in this paper, which is based on the
finite-difference time-domain (FDTD) approximation to Maxwell's
equations self-consistently coupled with a fluid model for plasma
evolution. The discharge characteristics at an input microwave power
of 1200~W and a filling gas pressure of 50~Pa in the SWP source are
analyzed. The simulation shows the time evolution of deposited power
density at different stages, and the 3D distributions of electron
density and temperature in the chamber at steady state. In addition,
the results show that there is a peak of plasma density
approximately at a vertical distance of 3~cm from the quartz window. 相似文献
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The mode transition of a pulsed vacuum arc discharge, which is from vacuum surface flashover to non-surface vacuum breakdown or vice versa, is studied by simply adjusting a trigger resistor. This approach provides a possibility to research the transition discharge process. Since the transition process is smooth and controllable, the transition mechanism and its effect on the performance of an ion source can be investigated via various diagnosis experiments. The experimental results show that the mode transition occurs when the resistance is in the range of 0- 10Ω. With the mode transition from surface flashover to non-surface vacuum breakdown, the vacuum arc discharge becomes more intense and the ion current produced by the Ti cathode ion source increases by two times. The related physical mechanism is also discussed in detail. 相似文献