共查询到18条相似文献,搜索用时 125 毫秒
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微型电子回旋共振(ECR)离子推力器可满足微小航天器空间探测的推进需求. 为此, 本文开展直径20 mm的微型ECR离子源结构优化实验研究. 根据放电室内静磁场和ECR谐振区的分布特点, 研究不同微波耦合输入位置对离子源性能的影响, 结果表明环形天线处在高于ECR谐振强度的强磁场区域时, 微波与等离子体实现无损耦合, 电子共振加热效果显著, 引出离子束流较大. 根据放电室电磁截止特性, 结合微波电场计算, 研究放电容积对离子源性能的影响, 实验表明过长或过短的腔体长度会导致引出离子束流下降甚至等离子体熄灭. 经优化后离子源性能测试表明, 在入射微波功率2.1 W、氩气流量14.9 μg/s下, 可引出离子束流5.4 mA, 气体放电损耗和利用率分别为389 W/A和15%. 相似文献
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低气压、低温放电方面的一个重要的最新进展是电子回旋共振(ECR)放电。这种技术首先是在核聚变研究中发展起来的。最初,它被用于磁镜实验装置产生和加热等离子体,后来,又被发展成为托卡马克、串级磁镜等聚变装置实验中进行等离子体加热的主要手段之一,即电子回旋共振加热(ECRH)。目前,这一高技术已被移植到各种低温等离子体应用之中,显示了蓬勃的生命力。电子回旋共振微波等离子体是指:当输入的微波频率ω等于电子回旋共振频率ωce时,微波能量可以共振耦合给电子,获得能量的电子电离中性气体,产生放电。电子回旋频率为ωce=eB/m,e和m为电子电荷及其质量,B是磁场强度。 相似文献
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衬底偏压对ECR等离子体鞘层和离子行为的影响 总被引:1,自引:0,他引:1
介绍了电子回旋共振微波放电等离子体中离子向衬底输运的蒙特卡罗模型,该模型考虑了精确依赖于离子能量的电荷交换和动量转移截面以及中性区与鞘层的衔接。 相似文献
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电子回旋共振(electron cyclotron resonance, ECR)源具有无需内电极、低气压电离、等离子体密度较高和结构紧凑等优点,适用于小功率电推进.因此,研究小功率碘工质ECR等离子体源具有重要意义.本文首先设计了一套耐腐蚀且可以均衡稳定输出碘蒸汽的储供系统;然后完成了耐碘腐蚀ECR推力器设计,利用耐腐蚀的同轴谐振腔结构将微波馈送到推力器,并将通道磁场变为会切型磁场以产生更多ECR层;最终联合点火实验成功,成为国际上首个可以用于电推进的ECR电离碘工质等离子体源.分析实验和静磁场、微波电场分布发现,小功率、低流量下的不稳定等离子体羽流闪烁由寻常波电子等离子体共振加热和非寻常波ECR加热模式之间的转化引起.高流量下电离率下降是由电子损失、壁面损失和碘工质电负性导致.并依据此原理提出了改进方案.放电后等离子体源没有明显损伤,说明具备长寿命潜力.此项工作初步证实了小功率碘工质ECR电推进方案可行. 相似文献
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研究了电子回旋共振等离子体增强化学气相沉积系统中栅网的增加和栅网上施加+60V和-60V偏压对CHF3放电等离子体特性的影响.发现在低微波功率下栅网与偏压对等离子 体中基团分布的影响较大,而高微波功率下的影响逐渐减小.这是由于低微波功率下等离子体中电子温度较低,基团的分布同时受栅网鞘电场和电子碰撞分解的共同作用;而高微波功率下电子温度较高,栅网鞘电场的作用减弱,基团分布主要取决于电子碰撞分解作用.
关键词:
电子回旋共振放电
3分解')" href="#">CHF3分解
栅网
偏压 相似文献
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介绍了回旋质谱探测器的原理和设计及其在HT-7 装置欧姆放电下对边缘等离子体中离子的诊断实验。探测器安装在限制器附近, 通过一小孔引进等离子体; 设置的前置偏压使电子和离子分离, 并使离子减速; 进入腔体内部的离子在射频电场和平行磁场的作用下发生回旋共振; 通过考察收集的离子电流信号中的共振峰可得到离子的荷质比、回旋频率等参数。实验中观察到荷质比为1、0. 5、0. 3333、0 . 1819 的离子共振峰。 相似文献
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Understanding hydrogen plasma processes based on the diagnostic results of 2.45 GHz ECRIS at Peking University 下载免费PDF全文
Optical emission spectroscopy(OES), as a simple in situ method without disturbing the plasma, has been performed for the plasma diagnosis of a 2.45 GHz permanent magnet electron cyclotron resonance(PMECR) ion source at Peking University(PKU). A spectrum measurement platform has been set up with the quartz-chamber electron cyclotron resonance(ECR) ion source [Patent Number: ZL 201110026605.4] and experiments were carried out recently. The electron temperature and electron density inside the ECR plasma chamber have been measured with the method of line intensity ratio of noble gas. Hydrogen plasma processes inside the discharge chamber are discussed based on the diagnostic results. What is more, the superiority of the method of line intensity ratio of noble gas is indicated with a comparison to line intensity ratio of hydrogen. Details will be presented in this paper. 相似文献
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Meyyappan R. Govindan T.R. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1995,23(4):623-627
A simple model to predict the spatially-averaged plasma characteristics of electron cyclotron resonance (ECR) reactors is presented. The model consists of global conservation equations for species concentration, electron density and energy. A gas energy balance is used to predict the neutral temperature self-consistently. The model is demonstrated for an ECR argon discharge. The predicted behavior of the discharge as a function of system variables agrees well with experimental observations 相似文献
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A technique is proposed for estimating parameters of the plasma produced by a source based on the electron cyclotron resonance. The analysis is made for the ion cyclotron resonance (ICR) facility designed for separating calcium isotopes. It is assumed that the resonance condition for an extraordinary wave is fulfilled for electrons moving towards the wave. The plasma optical thickness, the transverse energy of resonance electrons, and its dependence on the longitudinal velocity are determined. The charged particle density in the plasma flow is estimated in terms of the balance of the electrons generated as a result of vapor ionization in the discharge zone and the electron losses due to longitudinal ambipolar diffusion. 相似文献
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WenBin Wu HaiTao Ren ShiXiang Peng Yuan Xu JiaMei Wen Tao Zhang JingFeng Zhang AiLin Zhang Jiang Sun ZhiYu Guo JiaEr Chen 《中国科学:物理学 力学 天文学(英文版)》2018,61(4):045211
A quartz-chamber 2.45 GHz electron cyclotron resonance ion source(ECRIS) was designed for diagnostic purposes at Peking University [Patent Number: ZL 201110026605.4]. This ion source can produce a maximum 84 m A hydrogen ion beam at 50 k V with a duty factor of 10%. The root-mean-square(RMS) emittance of this beam is less than 0.12π mm mrad. In our initial work,the electron temperature and electron density inside the plasma chamber had been measured with the line intensity ratio of noble gases. Based on these results, the atomic and molecular emission spectra of hydrogen were applied to determine the dissociation degree of hydrogen and the vibrational temperature of hydrogen molecules in the ground state, respectively. Measurements were performed at gas pressures from 4×10~(-4) to 1×10~(-3) Pa and at input peak RF power ranging from 1000 to 1800 W. The dissociation degree of hydrogen in the range of 0.5%-10% and the vibrational temperature of hydrogen molecules in the ground state in the range of 3500-8500 K were obtained. The plasma processes inside this ECRIS chamber were discussed based on these results. 相似文献
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L. Celona S. Gammino F. Maimone D. Mascali N. Gambino R. Miracoli G. Ciavola 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2011,61(1):107-115
Ion sources have a significant number of applications in accelerator facilities and in industrial applications. In particular,
the electron cyclotron resonance ion sources (ECRIS) are nowadays the most effective devices that can feed particle accelerators
in a continuous and reliable way, providing high current beams of low and medium charge state ions and lower, but still remarkable,
beam current for highly charged ions. In recent years several experiments have shown that the current, the charge states and
even the beam shape change by slightly varying the microwave frequency (the so-called frequency tuning effect – FTE). The
theoretical explanation of these results is based on the difference in the electromagnetic field pattern over the resonance
surface, i.e. that region where the electrons resonantly interact with the incoming wave. In order to be consistent with the
experiments, this model requires that standing waves are formed also in presence of a dense plasma. The proof was sought by
means of a series of measurements performed with a network analyzer and with a plasma reactor operating at 2.45 GHz, according
to the principles of the microwave discharge ion sources (MDIS). The measurements have been carried out with the aim to achieve
the electromagnetic characterization of the plasma chamber in terms of possible excited resonant modes with and without plasma,
and they reported that resonant modes are excited inside the cavity even in presence of a dense plasma. It was observed that
the plasma dynamics strongly depends on the structure of the standing waves that are generated. The measurement of the eigen-frequencies'
shifts were carried out for several values of pressure and RF power, thus linking the shift with the plasma density measured
by a Langmuir probe. The changes in plasma shape, density and electron temperature have been also monitored for different
operating conditions. A strong variation of plasma properties has been observed as a consequence of the introduction of the
Langmuir probe inside the resonant cavity, thus demonstrating that the standing wave can be strongly perturbed even by means
of relatively small metallic electrodes. The measurements reported hereinafter are relevant also for ECRIS, because they confirm
the validity of the theoretical model that describes the frequency tuning. 相似文献
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Koon S. Nak-Heon Choi Hyoung-Bin Park Duk-In Choi 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1995,23(4):609-616
A one-dimensional fluid model of the microwave electron cyclotron resonance (ECR) discharge, which includes the inhomogeneity effects of the external magnetic field, is developed. We use fluid equations which are obtained from the one-dimensional Bolzmann equation expressed in terms of magnetic moment and parallel velocity. We model the plasma and sheath separately, and appropriate plasma-sheath boundary conditions are utilized. Microwave is represented by an energy flow, and treated by a ray tracing technique. For the argon discharge, we obtain various quantities such as the axial profiles of plasma density, electron temperature, electrostatic potential, fluid velocity, and microwave power deposition. The results of simulation compare well with the experimental observation of the mirror field effects on the plasma parameters 相似文献
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为更好地理解放电腔内等离子体物理机制,对Kaufman型离子推力器放电腔进行了数值研究,其中初始电子采用粒子模拟的方法处理,二次电子和离子采用漂移-扩散流体近似描述。模拟结果与已有实验测量数据进行对比表明:所采用计算方法适用于放电腔内等离子体流动规律的数值研究;模拟得到的稳态下等离子体分布及变化规律与实验测量数据相吻合;磁场的设计对初始电子起到显著的约束作用,有效地提高了其与工质气体的电离碰撞几率;二次电子的精确描述还需在流体方程中耦合磁场效应。 相似文献