This paper mainly study on the technics of preparing nano - si3n4 and icpecvd . seeking for the proper parameter and technics , crystallization of nano - si3n4 powder with muffle furnace , probe the new effective way of improving the properties of nano - si3n4 powder the ion density in the reaction chamber was diagnosed by a langmuir probe . the rules were obtained under different air pressure , different radio frequency power and different position which the ion density changes about from 1010cm - 3 to 1010cm - 3 decreasing as the pressure increases and increasing as the power decreases 利用朗缪尔探针诊断了反应室内等离子体参数，得到不同位置、不同功率和不同气压下等离子体密度的变化规律，结果表明离子密度为10 ~ 8 10 ~ ( 10 ) cm ~ ( - 3 ) ，等离子体密度随着功率的增大而增大，随着气压的升高而减小，由于离子鞘层的存在，在一定条件下提供了局部等离子体密度稳定的区域。
By film thickness measured , fourier transformed infrared spectrometer ( ftir ) analysis , x - ray photoelectron spectroscopy ( xps ) analysis and relative irradiance measurement , the effect of microwave input powers on deposition rates , f / c ratios , bonding configurations of ct - c : f films and the radicals in plasma originating from source gases dissociation is analyzed 由于微波功率的改变会导致等离子体中电子温度和等离子体密度发生变化，从而造成不同的源气体分解过程，结果微波功率的升高导致了薄膜沉积速率的提高、 f / c比的降低，同时也导致薄膜中cf和cf _ 3基团密度的降低，而保持cf _ 2基团密度接近常数。
A dfdl model including gain saturation effects is developed and this model is used to study the fluctuation of the pulse width theoretically , which is identical to the experiments . in order for ps pulse amplification , the saturation fluence for krf at 10 ps and gain of the discharge krf laser are monitored . 4 开展了10pskrf激光在空气中的传输实验研究，计算了自导引区内的阈值光强，观测到光束自聚焦和自导引现象，测量了自导引区域内的等离子体密度，并对激光脉冲的传输演化进行了分析。
Numerical simulations were done to show the distortion of the wavefront and the interference pattern under several kinds of typical plasma density distributions . the ray path in plasma was calculated by the numerical solution of the vector equation of light ray , when the plasma density was closing to the critical electron density of the laser frequency . through the simulations , the factors that influence the measurement were found out under different density distributions and shapes of plasma 在此基础上，采用数值模拟的方法，计算了在几种典型的等离子体密度分布下，激光波面的变化和产生的干涉图样；并用光线矢量微分方程的数值解法计算了当等离子体密度接近光频临界电子密度时，光线在等离子体中的传播路径，从中掌握了在不同的等离子体密度和形状下，进行干涉测量所应估计到的因素。
In this paper , we focus on the following three topics : ( i ) density distribution of dusty plasma in the low - pressure collisionless positive column the radial density distributions of electron , ion and dust particle in the low - pressure collisionless positive column are investigated with a fluid theory and a self - consistent dust - charging model 本文着重以下三个方面的研究： ( )低气压无碰撞辉光放电正柱区尘埃等离子体密度径向分布本文采用流体模型和自洽的尘埃充电模型，研究了低气压无碰撞辉光放电正柱区的电子密度、离子密度和尘埃粒子密度的径向分布。
In the hipib film deposition , high purity graphite was employed as target . relations between process parameters and the microstructure , as well as different physical properties of diamond - like carbon ( dlc ) film deposited by hipib ablated plasma were studied by adjusting the distance between target and substrate , which affects the intensity and ion energy of hipib ablated plasma , and the temperature of substrate in the film deposition processes . the mechanism of film deposition by hipib ablated plasma was explored also 在薄膜沉积方面，利用高纯石墨作靶材，调整薄膜沉积过程中的靶基距(烧蚀等离子体密度、离子能量)和基片温度，研究实验工艺对hipib烧蚀等离子体方法制备的dlc薄膜的微观结构和宏观物理性能的影响，探讨了hipib烧蚀等离子体沉积dlc薄膜的成膜机理。
To make pic ( particl - in - cell ) simulations . to set up models of guns and magnetic field and simulate them in the vacuum and plasma , respectively . we found that plasma held back part of space charge effects and improved trajectory of electrons . but beam would oscillate and became instable as accretion of plasma density . by simulating again and again , we draw a conclusion magic could n ' t work when plasma density was more by far than beam electron density . at last a four - stage depressed collector was simulated 建立电子枪和聚焦系统模拟模型,分别在真空和填充等离子体条件下进行模拟。发现填充等离子体能补偿部分空间电荷效应,改善电子束包络轨迹,提高电子的流通率,但是随着等离子体密度的增大,束电子会出现振荡不稳定性,遗憾的是通过反复多次模拟发现本文所用粒子模拟的代表性软件magic无法用于模拟等离子体密度远高于束电子密度的情况。
This effects can be explained as follows : the radiation conditions are actually impedance matching condition in terms of microwave network , for a fixed dimension of a resonator and output transformer , only below the critical plasma density " , the matching condition can be satisfied in the smith circle map 我们提出，这一现象可从阻抗匹配的角度来解释。对于一确定尺寸的腔体、阻抗变换器，存在一个等离子体密度的临界值，只有在等离子体密度低于这个临界值时，腔体的输出阻抗和波导的特性阻抗才能满足匹配，即满足所谓的辐射条件。
The aim of this paper is to search for a new type periodic slow - wave structure with filling periodically magnetized plasma , and following works are done : 1 . firstly , the investigation of wave propagation characteristic in magnetized plasma with periodically changing density is done . by numerical calculation , analyze the effect of additional magnetic field and plasma density changing on the propagation characteristic 本文的目的是探索一种周期磁化等离子体慢波结构,并做了如下的工作: 1 .对电磁波在密度周期变化磁化等离子体中的传输特性进行了研究,通过数值计算分析了不同外加磁场以及不同等离子体密度情况下波的传播特性。
The scaling relations of conduction time and opening time with the plasma density , which are computed by a series of simulation results , show that , influence of plasma density on conduction time is greater than opening time . influence of cathode em itted electrons on conduction process , which is found to be more important when initial plasma density is low , is dependent of the initial plasma density . the penetration of a magnetic field into cylindrical middle - density ( 1013 / cm3 ) c + + and h + plasma with uniform and parabolic density profile , are examined with aid of pic simulation 模拟得到的低密度( 10 ~ ( 11 ) cm ~ 3 10 ~ ( 13 ) cm ~ 3 )条件下导通和断路时间与等离子体密度的定标关系曲线显示：密度对于导通时间的影响远大于对于断路时间的影响；阴极电子对于peos导通过程的影响程度与初始等离子体密度有关，初始密度越大，阴极电子的影响就越小。
