共查询到20条相似文献，搜索用时 46 毫秒
1.
采用蒙特卡罗模拟对氮辉光放电等离子体中轰击极阴的重粒子（N2^ ,N^ ,Nf及N2f）能量分布随放电参数的变化规律进行了研究。结果表明：阴极臂前诸粒子的能量分布取决于粒子被加速的能量和碰撞频率,能量较低的快原子Nf的密度比高能粒子N^ 的密度最近两个量级。在活性氮粒子（N^ ,Nf）产率最高的放电条件下,适当降低放电气压,提高阴极位降和气体温度,有利于两种活性氮粒子（N^ ,Nf）达到阴极。 相似文献
2.
For the purpose of investigating impurity deposition and fuel retention in gaps between divertor tiles, we combine a three‐dimensional Monte Carlo impurity transport code ITCD with a Particle‐In‐Cell Monte Carlo collision code plus a plasma‐surface interaction (PSI) code. The simulation results show that a potential hill formed near the entrance of the gap can prevent the ionized eroded carbon species from entering the gap. It is found that carbon sources for the co‐deposition in gaps are mainly located at the plasma‐closest edges of the gap, and this finding indicates that special measures associated with the engineering issues should be taken to minimize fuel retention in gaps. The smaller scale of carbon sources inside the gap and the existence of the potential hill near the entrance of the gap are the reasons why the eroded carbon species spatial density is lower inside the gap than outside the gap. Through the study on several scenarios with different substrate and plasma temperatures, the simulation with the combined code can deepen the understanding of fuel retention in the codeposited layers in gaps (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
3.
4.
N. Kh. Bastykova A. Zs. Kovács I. Korolov S. K. Kodanova T. S. Ramazanov P. Hartmann Z. Donkó 《等离子体物理论文集》2015,55(9):671-676
Experiments and particle‐based kinetic simulations were performed to obtain the equilibrium levitation height of dust particles in plane parallel electrode discharges in low pressure argon gas, established by combined RF and DC excitation. The computed values were compared to experimental data. The good overall agreement of the simulation results and the experimental data verifies our gas discharge, dust charging, as well as dust force balance models. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
5.
To investigate carbon‐based material erosion and ensuing eroded carbon species density distribution, a Particle‐In‐Cell Monte Carlo collision code plus a plasma‐surface interaction code were combined with a Monte Carlo impurity transport code ITCD. It is found that a “density hill” forms at a distance of 3‐4 mm from divertor target plate under certain circumstances: high plasma temperature, small incident angle and strength of the magnetic field. By means of the study with the combined code on several scenarios with different plasma temperatures, the incident angles and strengths of the magnetic field, the simulation results reveal that they have a significant influence on the chemical erosion of carbon‐based material and the spatial distribution of eroded carbon species density above divertor target plate: the eroded carbon species density is smaller at a lower plasma temperature; the scenario with smaller incident angle and greater strength of the magnetic field can reduce the chemical erosion of carbon‐based material and the eroded carbon species density above divertor target plate evidently (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
6.
采用自动调节时间步长的蒙特卡罗模拟,对平行板放电系统中的氩气直流辉光放电系统中的等离子体区内电子的运动过程进行了跟踪和抽样。统计结果表明:在我们的实验条件下,等离子体中的电子在电场作用下出现明显的轴向漂移;在40000次抽样中,出现能量为E的电子数目随能量E增大呈下降趋势,场强增大将引起能量分布展宽和电子平均能量增加;即使场强达到15V·cm-1,等离子体激发和电离仍是很少的;场强和气压都能明显改变电子的平均自由程。 相似文献
7.
开发了氮空心阴极放电PIC/MC二维自洽模型。研究了N2传统空心阴极向微空心阴极放电转变过程中电势和电场的变化。结果表明,不同尺寸的空心阴极放电的电势及电场分布规律几乎类似,但空心阴极孔径减小且气压增加时,电场近似线性增加;典型微空心阴极电场比传统空心阴极放电电场约大3个量级;微空心阴极放电产生的电子,氮分子离子和氮原子离子的密度比传统空心阴极放电约大3个量级,且微空心阴极放电中,N2+密度比N+密度大8倍以上。 相似文献
8.
利用蒙特卡罗方法模拟氩气直流辉光放电鞘层内离子的运动过程.模拟基于离子与中性原子的电荷转移和弹性散射两种主要的散射过程,考虑了碰撞截面与能量相关和不相关两种情况,在弹性散射中采用了势场相互作用模型和刚性球碰撞两种模型.通过模拟得到不同气压和不同放电电压下离子入射阴极的能量分布和角度分布,并对几种模型的模拟结果进行了比较和讨论.关键词：辉光放电等离子体鞘层蒙特卡罗模拟 相似文献
9.
10.
为更好地理解低气压、弱电离条件下潘宁离子源放电过程中离子和电子的动力学行为, 通过建立二维轴对称模型, 采用粒子模拟与蒙特卡罗相结合(PIC/MCC)的方法, 考虑了电子与氢气之间的弹性碰撞、激发、电离以及氢原子、离子之间的弹性碰撞和电荷交换等过程, 对微型氢气潘宁离子源放电和引出过程进行了数值研究. 考察了磁场位形、壁面二次电子发射系数、引出电压和充气压力对放电过程的影响, 得到了实验中难以诊断得到的放电腔内电子与离子数密度分布, 阳极电流、引出极离子电流、单原子氢离子比例和双原子氢离子比例等宏观参数与实验结果相一致. 通过仿真使得对氢气潘宁放电机制的研究从定性过渡到定量, 这对于潘宁离子源的设计和改进具有重要意义.关键词：潘宁放电氢气粒子模拟蒙特卡罗 相似文献
11.
本文介绍了一种改进型的微波等离子体增强辉光放电光源。对它的结构，操作以及工作参数和溅射等进行了详细的讨论。 相似文献
12.
A bit-string model for biological aging 总被引：1，自引：0，他引：1
T. J. P. Penna 《Journal of statistical physics》1995,78(5-6):1629-1633
We present a simple model for biological aging. We study it through computer simulations and fint it to reflect some features of real populations. 相似文献
13.
14.
15.
Hugo O. Mosca 《Surface science》2007,601(15):3224-3232
The surface energy for different surface orientations of the solid solutions as a function of concentration formed by Ti, V, Cr, Zr, Nb, Mo, Hf, Ta, and W is computed and analyzed using the BFS method for alloys. Similarities and differences among the different binary alloys are examined in terms of strain and chemical effects. 相似文献
16.
惯性约束聚变研究中,热辐射光子在介质中的输运以及热辐射光子与介质的相互作用是重要研究课题,蒙特卡罗方法是该类问题的重要研究手段之一.隐式蒙特卡罗方法虽然能正确地模拟热辐射在介质中的输运过程,但当模拟重介质(材料的吸收系数大)问题时,该方法花费的计算时间将变得很长,导致模拟效率很低.本文以离散扩散蒙特卡罗方法为基础,开发了"离散扩散蒙特卡罗方法辐射输运模拟程序",可以较好地解决重介质区的计算效率问题,但是离散扩散蒙卡罗方法在模拟轻介质区时精度不够高.辐射输运问题中通常既有轻介质也有重介质,为了能同时解决蒙特卡罗方法模拟的效率和精度问题,本文研究了离散扩散蒙特卡罗方法与隐式蒙特卡罗方法相结合的模拟方法,并提出了新的扩散区与输运区界面处理方法,研制了混合蒙特卡罗方法的辐射输运模拟程序.典型辐射输运问题模拟显示:在模拟重介质问题时,该程序能大幅缩短模拟时间,且能取得与隐式蒙特卡罗方法一致的结果;在模拟轻重介质均存在的问题时,与隐式蒙特卡罗方法相比,混合蒙特卡罗方法的模拟精度与其相当且计算效率同样能够得到显著提升. 相似文献
17.
空气中的大气压辉光放电通常因放电易过渡到火花状态而难以产生。在静态大气压空气针-板等离子体发生器中，采用阻容耦合负反馈方法控制等离子体放电发展过程，成功地抑制了辉光放电向火花放电的过渡，产生了稳定的交流辉光放电。研究了电压、电极间距等参数变化对放电的影响。 相似文献
18.
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
19.
建立了电子回旋共振（ＥＣＲ）微波放电等离子体中离子输运过程的蒙特卡罗模型，考虑了离子与中性原子的电荷交换碰撞和弹性碰撞，以及精确依赖于离子能量的电荷交换和动量转移截面，模拟了源于氩气ＥＣＲ微波放电的氩离子向衬底输运的过程，得到与实验报道相符的模拟结果。 相似文献
20.
采用粒子模拟与蒙特卡罗相结合(PIC/MCC)的方法对电子回旋共振(ECR)放电中的电离过程进行了模拟,其中带电粒子与微波的相互作用由PIC方法的电磁模型描述,粒子间的碰撞过程由MCC方法描述.考虑的碰撞类型有电子与中性粒子的弹性、激发、电离碰撞,离子与中性粒子的弹性、电荷交换碰撞,碰撞截面均依赖于能量而变化.阐述了理论分析的过程,为数值模拟ECR放电奠定了基础.关键词：电子回旋共振放电粒子模拟蒙特卡罗电离 相似文献