HT—6M上电荷交换中性粒子能谱测量

用10道电荷文换中性粒子分析器测量了HT-6M装置的中性粒子能谱,给出了测量和数据处理方法以及在欧姆加热,高能中性粒子束(NBD)和离子回旋共振辅助加热(ICRH)条件下的能谱和离子温度,并对结果进行了分析讨论。     

HL—1M中性束注入期间离子温度的变化

在ＭＬ－１Ｍ中性束注入期间,我们用电荷交换中性普子能谱仪测量了等离子体离子温度的。结果表明,加热效果比较好时,离子温度可提高１倍左右。     

HT-6M中性束注入加热理论分析

通过数值求解含时、二维(速度空间)、非线性的Fokker-Planck方程,计算了HT-6M托克马克在中性束注入加热条件下的离子温度、分布函数随时间的演化.随着中性束的注入,离子温度稳步增加,分布函数出现高能平台和非同向分布,计算结果和现有的实验符合较好. 关键词：     

HT—6M装置中性束注入加热初步实验

一、引 言 在受控核聚变领域中,中性束注入是加热高温等离子体最有效方法之一。目前,几乎所有托卡马克实验中所获得高的温度,都是在有中性束注入情况下实现的。而用中性束注入加热托卡马克等离子体在国内尚属首次。 中性束注入系统的关键是离子源引出高能离子束,经过中性化室将高能离子束转变成高能中性束,并注入到装置中去加热等离子体,以提高等离子体的离子温度。 该系统涉及技术领域广,工程量大,经过多年艰苦努力,HT-6M装置中性束注入系统,终于进入实验阶段。本文介绍当50kW中性束注入HT-6M装置后,等离子体温度净增约80eV。     

HT-6M托卡马克离子回旋共振频率加热电荷交换能谱的分析

介绍了用电荷交换分析器测量了HT-6M托卡马克离子回旋共振频率加热时的氢离子能谱,观察到离子温度的增加.根据Fokker-Planck方程计算的电荷交换能谱和离子温度与实验结果比较,两者符合得很好. 关键词：     

HL—1M装置等离子体离子温度测量

在ＨＬ－１Ｍ托卡马克装置上，利用８通道中性粒子能谱仪测量的等离子体离子温度。在等离子体电流和密变化、激光吹气、弹丸注入，超声分子束注入和低混杂波加热等实验条件下，观测了Ｔｉ的变化。     

红外激光和远红外激光的汤姆逊散射

在受控热核反应的研究中,等离子体的离子温度是实现受控“点火”的一个极重要的参数.应用红宝石激光的汤姆逊散射可以正确地测量等离子体的电子温度和电子密度.但要用来测量离子温度的话,则由于散射角太小,杂散光太大,在技术上变得非常困难.只有应用电荷交换的中性粒子能谱分析的方法才可以测量离子温度.可是,在较高的粒子密度或等离子体装置较大的情况下,由于等离子体的线度大于中性粒子的平均自由程,这种方法也就无法测量等离子体内部的离子温度.如果使用光谱分析的方法,由于存在杂质辐射,在技术上是很困难的.并且分辨率很差.因此,迄今为…     

在托卡马克装置杂散磁场下未中性化离子偏转轨道的计算与分析

本文给出了在托卡马克装置杂散磁场下中性束注入器内未中性化离子偏转轨道的计算结果,并分析了在装置的中性束注入器上实现的可能性。     

HL—1M装置1998年物理实验进展报告

报道了ＨＬ－１Ｍ装置１９９８年度物理实验的进展情况。主要包括等离子体密度极限,中性束注入加热,离子回旋共振加热,低温杂波离子加热,多发弹丸注入,超声分子束注入等实验的情况。     

高能中性束注入加热

本文仔细地研究了高能中性束注入加热的有关问题,利用多束模型计算了中性束注入加热。本文的主要特点是在捕获快离子与本底离子和电子能量交换表示式中,直接用误差函数积分进行计算,而不像以前的计算中作大参量和小参量展开近似。当快离子能量比较低时,大参量展开不再适用,因此本文的计算更为精确,更为有用。给出了多束注入加热的计算结果及其结果的讨论。本计算方法可与输运方程联立求解,数值模拟等离子体行为。     

HT-7质能分辨电荷交换中性粒子分析

一台新的10道电荷交换中性粒子能谱仪已用于HT-7托卡马克装置等离子体测量.它具有磁场和电场，且在能量0.2—50keV范围进行了标定.新的能谱仪对于电荷交换粒子测量既能质量分辨，又可能量分析，还能提供空间多点扫描.在欧姆加热氘放电期间，进行了较大角度范围内的径向扫描离子温度测量，得到了HT-7托卡马克离子温度的时间和空间分布. 关键词：     

An Improvement of Secondary Emission Detector for Energy Analysis of Charge-Exchange Neutrals Emitted from High-Temperature Plasma

Secondary emission detector (SED) is improved for ion temperature measurement of high-temperature plasma by charge-exchange neutral analysis. This improvement is based on the incident energy (E) dependency of the ratio of secondary electron yield for an incident angle ? to that for normal incidence, defined as k(?, E). The ratio k(?, E) is investigated as functions of E and ? for hydrogen atom incidence. To examine and demonstrate the usefulness of the improved SED, both experimental simulation and computer simulation of the charge-exchange neutral analysis with the improved SED are used. In the experimental simulation, facsimile neutrals are produced by neutralization of an ion beam on a solid surface and are analyzed by the improved SED. The result is compared with that obtained by using normal charge-stripping type analyzer. In the computer simulation, a simple model of the charge-exchange neutral emission of high-temperature hydrogen plasma is assumed and the usefulness of the improved SED as a hydrogen plasma diagnostic technique is evaluated under the influences of strong plasma radiation conditions.     

Hα线型分析

利用高斯分布拟合HT-6M托卡马克Hα线型，得出了由反射进入等离子体中的氢原子、氢分子离解后产生的氢原子，以及电荷交换产生的氢原子辐射Ｈα谱线的份额，由Doppler频移和展宽分别得出它们的入射速度和离子温度．在简化模型下讨论了氢原子的输运行为，得出了氢原子的密度分布和体发射系数，以及入射速度大小对粒子约束时间的影响，并与实验数据进行比较．由中性氢原子能量分布得出发生在边界的分子过程是氢分子的离解激发和电离离解 关键词：     

Experimental study of the influence of the processes in the ion-beam drift space on beam current measurements

A method is proposed for separate measurements of the current produced by slow charge-exchange ions and that produced by the ions generated due to gas ionization by the beam ions and fast secondary electrons in the beam drift space. The method is based on an analysis of the current distribution over the electrodes of a modified Faraday cup with nonequipotential electrodes and allows one to determine the coefficient of ion-induced electron emission from the ion collector and the charge-exchange cross section of the accelerated ions. The method has been employed to measure the current of an argon ion beam with an ion energy from a few electronvolts to several tens of kiloelectronvolts and to study the processes in the beam drift space at pressures of 0.03–0.15 Pa.     

Numerical modeling of low-pressure RF plasmas

A particle-in-cell simulation is used to model the plasma generated in a parallel plate RF reactor at low pressure. Nonperiodic boundary conditions are used, and the electric field and particle motion are obtained by finite-difference methods leading to the self-consistent creation of sheaths on the boundaries. Model cross sections are used to describe collisions between particles. Ionization is included, and the plasma is maintained by fast electrons generated in the RF sheaths. Most of the power dissipation is due to the acceleration of ions in the time-average sheath fields. At high applied voltage, the power dissipation is described well by the power law P∝V^5/2. Simple scaling laws for the density and plasma potential are obtained. The effect of ion mass and charge-exchange colisions on the ion energy spectrum collected by the electrodes is examined. The ion loss rate drops in the presence of charge-exchange collisions, and this leads to an increase in the density. The collisions also markedly alter the ion energy distribution function     

Inelastic interaction of low-energy Ar ions with some hydrocarbon molecules

The theoretical studies of low-energy Ar⁺ ion charge-exchange at small carbon clusters are presented. The studies were conducted by means of computer simulation. From the investigations we concluded that the results of the ion charge-exchange at these clusters are determined by the clusters bond types.     

原子过程对极向CXRS测量影响的数值模拟

考虑到原子过程的影响，对极向CXRS测量过程进行了数值模拟.计算结果表明由于受辐射率 、回旋运动以及离子辐射寿命的影响，测量的结果会在离子逆磁漂移方向高估了离子的旋转 速度，而低估了离子的温度.这种偏差会随着离子温度的升高、磁场的增加而增大.相对与原 子过程的影响来说，由于等离子体非均匀性所引起的速度和温度的偏离很小，可以忽略不计 . 关键词： 原子过程 数值模拟 等离子体     

The experimental and computer studies of the double-scattering effect for polycrystals

The effect of double scattering of 10–35 keV Ar ions by a copper polycrystal has been studied in the case of asymmetric reflection. Contributions from collisions of various multiplicities to the obtained energy spectra have been analysed theoretically. The spectra are computer-calculated using the statistical trial method with due account for a discrete set of possible distances between the surface atoms which scatter the ions. The charge-exchange processes are also included in the calculations.     

Population-modulation study of the filling of mercury ion levels in a He-Hg discharge

The branching ratios for the lines at 615.0 nm and 794.5 nm and the ratios of the partial chargeexchange cross sections are determined through a comparison of the intensities of spectral lines of the mercury ion in a He-Hg discharge with and without emission at the 615.0-nm line (by the population-modulation method). Absolute values are found for the partial cross sections from the calculated contribution of the Hgll levels to the total charge-exchange cross sections. Observations of the shape of the spontaneous afterglow of the lines of the one-electron and Beitler spectra of Hg II and measurements of their intensities show that the charge-exchange cross section is distributed in proportions of approximately 37 between the levels of the one-electron and Beitler spectra of Hg II.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, pp. 90–97, May, 1984.     

EAST H模等离子体中离子内部输运垒特性 的初步实验研究

为了研究EAST上H模等离子体中离子内部输运垒(ITB)的特性，利用电荷交换复合光谱诊断，分析了离子ITB形成和稳态阶段等离子体离子温度和环向旋转速度的时空演化。结果表明，在离子ITB形成和稳定期间，ITB肩部附近(R=1.928m)的离子温度梯度增加时，ITB区域(R=1.984m)的离子温度梯度会有所降低，反之亦然。考虑到在离子ITB形成前，芯部区域不同半径位置的离子温度梯度同时增加或减小，得到了在R=1.984m处判断离子ITB是否形成的归一化离子温度梯度的阈值。