环流器等离子体高n气球模的第二稳定区

本文讨论了圆截面高比压等离子体关于高n气球模的稳定性,在高比压情况下,相应的极向磁场对气球模有相当强的驱动作用,从而严重影响了第二稳定区的结构,我们详细计算了不同剪切、不同压强梯度及不同极向场参数对气球模本征函数和本征频率的影响,这些结果比较完善地反映了圆截面环流器中理想磁流体气球模理论所预示的主要结论。 关键词：     

Tokamak plasma equilibrium analysis based on the relaxation method with a specified magnetic axis

In this contribution, we have presented two techniques for the determination of plasma equilibrium position in IR-T1 tokamak: relaxation and optical methods. An analysis method of tokamak plasma equilibrium by a relaxation method with a specified magnetic axis is presented. The degrees of freedom due to designated positions of the magnetic axis are possible by using poloidal field coil currents. Stable steady-state tokamak plasma equilibria are calculated along with the magnetohydrodynamic potential energy. The plasma generates a plasma current which partially or fully cancels the magnetic field from the poloidal field coils. For low-temperature plasmas, the plasma current distribution is centrally peaked; for high-temperature plasmas, the plasma current has a hole. A centrally peaked current distribution in a low-temperature plasma is evolved into a current distribution with a hole by increasing the plasma pressure by Ohmic heating, radio frequency heating, or by neutral beam injection heating. In the second technique, an image-processing technique was used for the output signal of the charge coupled device camera and plasma emission intensity profile and then the plasma position was obtained. Results are compared and discussed.     

HL-2M 装置磁测量系统设计及初始放电实验结果

介绍了 HL-2M 装置上满足等离子体放电的磁测量系统的物理设计,主要包括磁探针、磁通环以及 电流测量系统的设计。通过 HL-2M 装置典型的放电位形参数对磁探针的极向布局、有效面积,磁通环的极向布 局以及测量等离子体电流的罗氏圈互感值进行了初步设计。目前,HL-2M 装置已经完成初始等离子体放电。各个 子系统均能达到其测量目标。      

HL-2A单零偏滤器的位形特征

利用积分方法对多种电流剖面下HL2A装置单零偏滤器位形特征进行了计算研究。积分方法的优点是可以在任意电流剖面下求解具有X-点的自由边界的Grad-Shafranov方程。对HL2A装置而言,大体上可以在合理设定的分界面形状下,经几次叠代计算出各组极向场线圈(垂直场,三对多极场和多极补偿场以及水平场)中的电流。HL-2A的单零偏滤器位形基本上是圆截面加上在X-点附近的局部形变。对刮离区和偏滤器靶板区磁力线特性进行了分析以确定偏滤器的品质。     

Upgrade of the magnetic diagnostic system for restart of HT-6M operation

The HT-6M tokamak at the Thailand Institute of Nuclear Technology has been restarted. In order to ensure the smooth breakdown of plasma and obtain plasma discharge parameters, optimization of the poloidal field coils and upgrade of the magnetic diagnostics are described in this article. A perfect null field (stray field in the main chamber < 10 G) is obtained using an ohmic heating field. To obtain important information about the plasma, an external magnetic diagnostics system is designed and calibrated, including a Rogowski coil (measuring plasma current), a magnetic probe (measuring external field), diamagnetic loops (measuring β_p) and so on. In order to realize high-frequency signal measurement and transmission, a series of frequency responses with the magnetic probe and transmission line are tested. Later, to verify the null field, a fitting code is developed to reconstruct the stray field in the vacuum chamber based on magnetic probe measurements and flux loops. The results show that the error is within 1.5%. This indicates the accuracy of the magnetic measurement system and ensures the preparation for the breakdown of plasma.     

Ӧ�ø���CCD����о�HT-7װ�ñ߽����������ת

在HT-7装置上建立了一套高速CCD可见光成像诊断,测量了边界等离子体的可见光辐射成像.在HT-7装置放电中,首次观察到在等离子体边界区域存在一条极向旋转的可见光辐射带,由CCD诊断系统得到其极向旋转的频率为858Hz.根据多道Hα阵列测量得到极向旋转频率为952Hz.多道磁探针信号测量发现,等离子体内部存在m/n=3/1的电磁模,该模的旋转频率为972Hz.从电子回旋辐射诊断系统得到的电子温度剖面发现该模的磁岛宽度约为2.5cm.     

应用高速CCD诊断研究HT-7装置边界等离子体旋转

在HT-7装置上建立了一套高速CCD可见光成像诊断,测量了边界等离子体的可见光辐射成像。在HT-7装置放电中,首次观察到在等离子体边界区域存在一条极向旋转的可见光辐射带,由CCD诊断系统得到其极向旋转的频率为858Hz。根据多道H_α阵列测量得到极向旋转频率为952Hz。多道磁探针信号测量发现,等离子体内部存在m/n=3/1的电磁模,该模的旋转频率为972Hz。从电子回旋辐射诊断系统得到的电子温度剖面发现该模的磁岛宽度约为2.5cm。     

The heavy ion beam diagnostic for the tokamak ISTTOK

In this paper we describe the heavy ion beam diagnostic for the tokamak ISTTOK, which has been designed to determine the temporal evolution of the plasma density, poloidal magnetic field and plasma potential profiles. This diagnostic makes use of a new type of high density caesium plasma source, a multiple cell detector and a fast data acquisition system. We describe the numerical code for trajectory and beam attenuation simulations, a method for the experimental determination of the poloidal field profile, the ion gun and the detection, control and data acquisition systems. Calibration tests and the first experimental results are presented     

托卡马克等离子体辐射诊断中的线积分辐射率

在托卡马克等离子体辐射诊断中,通过阿贝尔反汪或层析分析从线积分辐射率中得到的空间分布,是辐射率在束线宽度范围内的平均值的分布,束线宽度限制了诊断的空间分辨能力。当探测器无穷小的近似条件不成立时。束线宽度显著大于探测器中心对光栏孔径张角决定的宽度,并且在给定束线截面内各点辐射对探测信号的贡献差别可能变得重要从而导致辐射率的宽度平均成为带权重的平均。     

Determination of Plasma Position Using Poloidal Flux Loops and Comparison With Magnetic Probe Measurement in IR-T1 Tokamak

In this paper, we present two magnetic techniques for the measurement of plasma position in IR-T1 tokamak: a poloidal flux loop and a magnetic probe method. In the first method, two flux loops were designed and installed toroidally on the outer surface of the IR-T1 tokamak, and then, displacement of the plasma column was measured from them. In addition, to compare the plasma position obtained using the flux loops, an array of four magnetic probes was designed, constructed, and installed on the outer surface of the IR-T1 tokamak, and plasma position was measured from them. Results were compared and found to be in good agreement with each other.      

利用高能锂束激光荧光法测量托卡马克中的角向磁场

本文介绍了利用高能锂束激光荧光法测量托卡马克中角向磁场的原理、实验装置和主要技术,同时也介绍了该方法的局限性。     

Analysis of the Zeeman effect on D_α spectra on the EAST tokamak

Based on the passive spectroscopy,the D_α atomic emission spectra in the boundary region of the plasma have been measured by a high resolution optical spectroscopic multichannel analysis(OSMA) system in EAST tokamak.The Zeeman splitting of the D_α spectral lines has been observed.A fitting procedure by using a nonlinear least squares method was applied to fit and analyze all polarization π and ±σ components of the D_α atomic spectra to acquire the information of the local plasma.The spectral line shape was investigated according to emission spectra from different regions(e.g.,low-field side and high-field side) along the viewing chords.Each polarization component was fitted and classified into three energy categories(the cold,warm,and hot components) based on different atomic production processes,in consistent with the transition energy distribution by calculating the gradient of the D_α spectral profile.The emission position,magnetic field intensity,and flow velocity of a deuterium atom were also discussed in the context.     

��̽������ı궨

为了标定EAST装置电磁测量系统中的磁探针位置偏差和回路增益,通过分析该装置中的误差源,设计了极向场线圈的通电模式。运用格林函数等算法程序对测量数据进行预处理,利用简化的泰勒线性展开,结合带权重的最小二乘法对数据进行多次循环迭代,拟合出磁探针的位置偏差和回路增益。实验结果表明,使用该方法标定是合理的。     

磁探针参数的标定

为了标定EAST装置电磁测量系统中的磁探针位置偏差和回路增益,通过分析该装置中的误差源,设计了极向场线圈的通电模式。运用格林函数等算法程序对测量数据进行预处理,利用简化的泰勒线性展开,结合带权重的最小二乘法对数据进行多次循环迭代,拟合出磁探针的位置偏差和回路增益。实验结果表明,使用该方法标定是合理的。     

Effect of parallel flows and toroidicity on cross-field transport of pellet ablation matter in tokamak plasmas

The first complete set of time-dependent equations describing the cross-field drift of ionized pellet ablation matter in tokamak plasma caused by polarization in the nonuniform magnetic field has been developed and solved numerically. Important new features impacting the drift dynamics have been identified, including the effect of pressure profile variations in the tokamak plasma, curvature drive by near-sonic field-aligned (parallel) flows, and the rotational transform of the magnetic field lines, and are considered from the viewpoint of the parallel vorticity equation. These new features are necessary to obtain favorable quantitative agreement between theory and experimental fuel deposition profiles for both inner and outer wall launched pellet injection cases on the DIII-D tokamak.     

托卡马克等离子体不同平衡位形下的电子回旋波电流驱动

在给定的等离子体总电流和中心电流密度条件下,数值求解平衡方程,求出不同拉长比和三角形变因子的托卡马克等离子体温度、密度、磁场分布,然后通过求解波迹方程和Fokker-Planck方程,分别计算这些位形下的电子回旋波波迹和电流驱动.结果表明：电子回旋波X模从顶部发射时,随着拉长比的增大,波迹会向弱场侧偏移.电子回旋波X模从弱场侧发射时,电子回旋波在等离子体中传播沉积的功率份额随着拉长比的增大而增加,驱动电流位置随着三角形变因子的增大向等离子体中心移动.驱动电流位置随环向和极向发射角的减小向中心移动,对应的电流密度峰值也变大.     

Magnetic Fluctuation Measurement in Sino United Spherical Tokamak Plasma

To investigate the magnetic fluctuations and for further transport study, the poloidal and radial magnetic field t is conducted on the Sino United Spherical Tokamak （SUNIST）. Auto-power spectral density indicares that the magnetic fiuctuation energy mainly concentrates in the frequency region lower than lO kttz. The magnetic field oscillations, which are characterized by harmonic frequencies of 40 kHz, are observed in the scrape- off layer; by contrast, in the plasma core, the magnetic fluctuations are of Gaussian type. The time-frequency profiles show that the poloidal magnetic fluctuations are temporally intermittent. The autocorrelation calculation indicates that the fluctuations in decorrelation time vary between the core and the edge.     

实验物理与工业控制系统平台在HL-2A主机测控系统中的应用

描述了利用实验物理与工业控制系统(EPICS)平台对HL-2A主机运行参数进行的集中测控系统开发。系统采用s7nodave设备驱动模块,实现了SoftIOC与各PLC的通讯,将各子系统的PLC集成到了EPICS控制系统中。通过对关系型数据库和应用层软件CSS中数据归档及报警等组件的扩展与配置,实现OPI层与各个子系统的实时通信。测控系统成功地将HL-2A主机参数集中在EPICS平台下运行,为下一代装置的主机集中测控系统设计打下了基础。     

含第二稳定区的环流器微观气球模分析

本文导出了可用于研究含第二稳定区的环流器微观气球模的本征方程,其中保留了各种最重要的动力效应。对圆截面环流器,相应的本征方程中保留了对第二稳定区中模的特性有重大影响的磁面位移效应及极向场曲率效应。采用数值打靶法求解本征方程,详细分析了各种位形参数对模的结构及稳定性的影响。与理想磁流体理论结果对比,发现在第二稳定区参数范围内,存在一类新的弱不稳定模式。此外,在各种参数范围内都存在临界稳定模式。详细考察了这些模式的存在形式及结构,以及剪切和极向场参数对它们的影响。 关键词：     

Measurement of safety factor using Hall probes on CASTOR tokamak

Hall sensors offer an attractive true non-inductive method of magnetic field measurements for fusion devices. However, there is only limited experience in using of these sensors in such demanding environment (high heat loads, radiation, and electromagnetic noise). Recently, a combined magnetic probe was developed for CASTOR tokamak, which contains 3 Hall sensors and 3 coils arranged to measure all three components of magnetic field approximately in a single point of space. The probe is compatible with in-vessel use well in confinement region of CASTOR. It is fully controlled by multi-functional electronic system that drives the Hall probes, amplifies their output signals, performs the A/D conversion and stores the measured data on PC. The bandwidth of the system is up to 200 kHz. Design of the system and its implementation on CASTOR is reviewed. Results obtained using this diagnostic on CASTOR tokamak is presented. Radial profile of the poloidal magnetic field is used to deduce radial profile of safety factor.