共查询到20条相似文献,搜索用时 421 毫秒
1.
本文采用新版的一维中性粒子输运程序,在平板几何下模拟了HL-1装置边缘8cm区域的分子过程及中性粒子与壁相互作用对中性粒子输运的影响,得到了电离速率的径向分布、稳态中性氢原子径向分布、壁与边缘等离子体区之间、芯部等离子体与边缘等离子体之间中性氢各种粒子通量、能量通量并与只含原子过程的类似计算进行了比较,结果表明边缘区的分子过程对巾性氢原子输运有显著的影响。有些结果得到实验的证实。 相似文献
2.
HT-6M托卡马克通过边界欧姆加热实现了改善约束的H模,利用中性粒子测量方法成功地研究了等离子体H模放电的中性粒子变化.观察到边界欧姆加热H模放电期间从等离子体逃逸的中性粒子比纯欧姆加热明显减少;约束改善后等离子体中心热区的中性原子密度下降,得到了反映等离子体约束改善的中性粒子特征.实验结果与其他诊断进行了比较和讨论
关键词: 相似文献
3.
4.
余德良 《核工业西南物理研究院年报》2006,(1):96-97
1引言
由于中性粒子不带电,因此不受磁场的约束,可以比较自由地出入等离子体区域。一方面,中性粒子输运直接影响主等高子体的能量平衡、动量平衡和粒子半衡;另一方面,研究中性粒子输运对等离子体诊断提供依据和分析对象。如逃逸的快中性原子可以被用来测量离子温度。 相似文献
5.
中性束注入(NBI)是托卡马克装置重要的辅助加热与电流驱动手段,中性原子的离化是决定中性束的加热(能量和粒子沉积剖面)和电流驱动效率的关键环节。通常情况下,利用背景等离子体参数与中性束参数模拟计算快的中性粒子与等离子体的离化,即中性束沉积过程,进而分析托卡马克中性束加热和电流驱动效果。束发射光谱是高能中性粒子注入等离子体后,与等离子体的电子、离子发生碰撞激发,中性粒子退激发过程中产生的一系列特征谱线,其束发射光谱强度受等离子体密度、温度、束能量、束密度等因素影响,可以利用束发射光谱强度变化研究中性束的衰减特性。在EAST托卡马克上通过实验测量中性束粒子与等离子体碰撞激发的光谱强度,分析得到了中性束在不同等离子体密度以及不同中性束能量下的衰减特性,并采用主动束光谱仿真与数值分析软件(SOS)进行了相应的模拟计算,研究表明实验测量与模拟计算结果两者具有较好的一致性,这验证了通过实验测量束发射光谱获取中性束衰减特征的可行性。 相似文献
6.
利用一个空间零维大气等离子体模型对其中的主要粒子在不同电离度情况下的变化规律进行了研究.得到放电后不同初始电子密度下的电子寿命,同时给出了主要带电粒子和中性粒子密度随时间的演化.结果表明,电子密度随时间快速衰减,电子寿命随电离度的增大而减小.对一些重要的中性粒子(如O,N,O3和NO)随电离度增大的行为进行了分析.
关键词:
电离度
大气等离子体
数值模拟 相似文献
7.
8.
在Zollweg & Liebermann模型(Z&L模型)的基础上,结合高温条件下的量子机理作用,考虑了电子与中性粒子的碰撞关系,最终得出修正后的电导率模型,并对局部热力学平衡状态下的水中放电等离子体的粒子数密度及电导率进行了模拟计算.计算结果表明压力为定值的情况下,水中放电等离子体的总粒子数密度随温度变化呈下降趋势,温度达到15000 K时,一次电离达最大值.电导率随温度增加总体呈上升趋势,温度低于12000 K时,电子与中性粒子的碰撞起主导作用,而温度高于25000 K时,电子与离子的碰撞起主导作用. 相似文献
9.
在ZollwegLiebermann模型(ZL模型)的基础上,结合高温条件下的量子机理作用,考虑了电子与中性粒子的碰撞关系,最终得出修正后的电导率模型,并对局部热力学平衡状态下的水中放电等离子体的粒子数密度及电导率进行了模拟计算.计算结果表明压力为定值的情况下,水中放电等离子体的总粒子数密度随温度变化呈下降趋势,温度达到15000 K时,一次电离达最大值.电导率随温度增加总体呈上升趋势,温度低于12000 K时,电子与中性粒子的碰撞起主导作用,而温度高于25000 K时,电子与离子的碰撞起主导作用. 相似文献
10.
11.
DENGBai-quan YANJian-cheng PENGLi-lin 《核聚变与等离子体物理》2005,25(2):139-145
A new bipartition neutral transport model has been developed for simulation of the hydrogenic neutral particle transport in the vicinity of HL-2A divertor target plate. The numerical calculation results on the basis of this model are fairly consistent with the results obtained with the “multi-generation method”. One possible application of this model is to provide a source term originating from neutral transport calculation for any other edge plasma transport code, for instance, B-2 code, which has been used to simulate edge plasma transport of the HL-2A divertor configuration. Especially it can be utilized to quickly classify the plasma in divertor region as high or low recycling regime. 相似文献
12.
Andrzej Baran Krzysztof Pomorski Michał Warda 《Zeitschrift für Physik A Hadrons and Nuclei》1997,357(1):33-38
Assuming a simple spherical relativistic mean field model of the nucleus, we estimate the width of the antiproton-neutron annihilation (Γn) and the width of antiproton-proton (Γp) annihilation, in an antiprotonic atom system. This allows us to determine the halo factor f, which is then discussed in the context of experimental data obtained in measurements recently done on LEAR utility at CERN. Another quantity which characterizes the deviation of the average nuclear densities ratio from the corresponding ratio of the homogeneous densities is introduced too. It was shown that it is also a good indicator of the neutron halo. The results are compared to experimental data as well as to the data of the simple liquid droplet model of the nuclear densities. The single particle structure of the nuclear density tail is discussed also. 相似文献
13.
在一维平板鞘层中应用流体模型研究了尘埃等离子体鞘层中碰撞对尘埃颗粒密度和带电量的影响。 研究所涉及的碰撞主要有电离碰撞,电子、离子分别与中性粒子的碰撞,以及电子、离子分别与尘埃颗粒的碰撞。通过采用四阶龙格库塔法,得到了数值解。结果表明,随着电离碰撞或者电子、离子分别与中性粒子碰撞的频率 增加,都将导致鞘层中尘埃颗粒的数密度增大,数密度的极值位置向鞘边位置靠近,尘埃颗粒带电量增多。电子、离子与尘埃颗粒的碰撞,使得尘埃带电量减小。此外,从研究的结果来看,由离子产生的碰撞要比电子产生的碰 撞对尘埃颗粒的影响明显得多。 相似文献
14.
�����ƣ��ű������ſ��� 《核聚变与等离子体物理》2014,34(3):207-213
The fluid dynamics model was used to study the influence of the existence of the collisions on the dust particles in a dusty plasma sheath. The main collisions in this study consist of the ionization collision, the collision between electron and neutral particle, the collision between ion and neutral particle, the collision between electron and dust particle, the collision between ion and dust particle. Numerical calculation results are obtained by the fourth-order-Rung-Kutta method. It is shown that both the dust particles’ density and corresponding electricity quantity increase as the following collisions’ frequency enhances, such as ionization collision, the collision between electron and neutral particle, the collision between ion and neutral particle. The charge reduces due to the collisions concluding electron-dust particle and ion-dust particle. In addition, the effect produced by ions’ collision is much more obviously compared with electrons’ collision. 相似文献
15.
Jürgen Freund 《Zeitschrift für Physik A Hadrons and Nuclei》1973,258(2):108-125
In pinch discharges a second plasma regime called halo1,2 outside the central plasma column1-4 has been observed. This surrounding plasma was investigated in the experiments with the 5.4 m long compression coil in the ISARI linear theta pinch because there it appears highly pronounced. The development of the discharge was observed side-on (stereoscopic) with image converters and a streak camera. It appears possible to resolve the space-time behaviour of the plasma, especially in the dynamic phase of the discharge where the halo shows a filament like structure, by using high-speed color reversal film (streak camera). Furthermore, the smear pictures show that after 6–8 μsec the halo region is frozen into the external magnetic field, that is from this time the halo is characterized by a high electrical conductivity. The boundary layer of the halo follows a magnetic flux tube. The parameters of the halo, such as electron densityn e (< 1015 cm?3), atomic temperatureT a , and ion temperatureT i (< 15 eV), were determined spectroscopically as a function of time and location from the broadening of the deuterium Balmer lines. The absolutely measured line intensities do not allow direct calculation of the electron temperature since the excited levels of the investigated Balmer lines are mainly populated from the ground level. By numerical solution of a system of rate equations describing the change of the levels a region for the electron temperature 5<T e <10eV can be specified. Different mechanisms, such as photoionization, ionization by electron impact in a time varying magnetic field, ionizing collisions of high velocity neutral atoms with neutral gas at rest, transport processes in the plasma across the magnetic field, instabilities which may cause the development of the halo, are discussed by means of the experimental results. It is concluded that the halo region is caused by flute instabilities. 相似文献
16.
煤粒均相着火规律的研究 总被引:1,自引:0,他引:1
煤粒均相着火规律的研究张军,傅维标(清华大学工程力学系北京100084)关键词均相着火,简化模型,预报1前言煤粉颗粒既能发生均相着火,又能发生非均相着火山。对非均相着火,许多学者进行了研究,取得了很多有价值的成果。均相着火由于比较复杂,一直发展缓慢。... 相似文献
17.
18.
ZHONG Guangwu ZHANG Jiquan SONG Xianming LU Jie ZHENG Yinjia ZHANG Guangyang WANG Quanming TANG Nianyi DENG Zhongchao DING Xuantong LIU Yong WANG Enyao 《核聚变与等离子体物理》2003,23(3):161-169
1 IntroductionConfinementandheatingofplasmasareele mentarytopicsinfusionresearch .Tocharacterizethefusionplasmasinauxiliaryheatingexperimentsaswellasinohmicheatingexperiments,measure mentofionenergyinplasmasbecomesnecessary .Neutralparticleanalyzersaresuchdevicesthatareaimedatdirectanalysisofneutralparticlesemittedfromfusionplasmasandareusedinmanyfusionresearchlaboratories[1~ 4] .Detailsofparticledi agnosticprincipleforfusionplasmacanbefoundinReference [5].Emissionofneutralparticlesisintrin… 相似文献
19.
20.
S. Yamaguchi K. Hirano 《Journal of Quantitative Spectroscopy & Radiative Transfer》1981,26(4):365-370
The neutral particle density of a deuterium plasma in the STP-2 screw pinch tokamak has been determined spectroscopically. The particle density for the ground state of deuterium is calculated from the rate equations for population density of the excited levels with principal quantum numbers 3 and 4; both of the population densities were obtained from intensities of the Balmer alpha and beta lines, and the rate coefficients for electronic collision were estimated from the electron density (1014/cm3) and temperature (10 eV) measured by laser scattering. We find that the neutral density is approx. 2 × 1012/cm3 at the center of the plasma and 2 × 1014/cm3 on the periphery. The time history of the neutral deuterium density is consistent with the observed increase in plasma density. 相似文献