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利用TSC程序对HL-2M装置的纯欧姆放电参数进行了首次数值放电模拟,证实了极向场线圈系统具有实现预设的宏观等离子体参数的能力。数值放电模拟还利用基本的位移控制和等离子体电流控制系统实现了从孔栏位形到下单零偏滤器位形的稳定演变。模拟提供的一些主要结果为工程和物理目标设计提供重要的参考。     

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。      

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用托卡马克模拟程序对实验前期的放电进行了模拟,获得了期望的等离子体演化过程及主要参数波形,如极向场线圈电流、等离子体电流、等离子体位置等。通过等离子体控制系统将模拟获取的参数波形用于实验,开展了等离子体R位置控制、完全程序场控制及RZIp控制下的放电模拟对实验的预测研究。模拟结果与实验吻合较好,表明放电模拟具有一定的可预测性,为今后EAST装置开展更深入的物理实验提供了一定的参考。     

EAST装置放电预测的初步研究

用托卡马克模拟程序对实验前期的放电进行了模拟,获得了期望的等离子体演化过程及主要参数波形,如极向场线圈电流、等离子体电流、等离子体位置等。通过等离子体控制系统将模拟获取的参数波形用于实验,开展了等离子体R位置控制、完全程序场控制及RZIp控制下的放电模拟对实验的预测研究。模拟结果与实验吻合较好,表明放电模拟具有一定的可预测性,为今后EAST装置开展更深入的物理实验提供了一定的参考。     

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.     

HT-7U托卡马克装置中超导螺管模型磁体的设计与实验研究

介绍了 TH- 7U超导 Tokamak核聚变装置中超导螺管模型磁体的设计过程及其电磁与力学性能分析。并通过对其进行的大型超导试验获得了一些重要参数 ,这些参数的取得将对 HT-7U装置中超导磁体的工程设计具有很重要的指导意义。     

HL-2M 装置支撑结构工程设计

HL-2M 装置的支撑结构系统,该系统由装置基础及重力支撑结构、极向场线圈及真空室支撑结构 和环向场线圈防倾覆支撑结构等三部分组成。本文介绍了 HL-2M 装置支撑结构工程设计情况。      

HL-2M装置环向场线圈导体材料的选择和制造

为利于HL-2M真空室(VV)及极向场线圈(PFC)的整体安装,环向场线圈(TFC)采用比特板式结构,这种结构需要用到高强度高导电性能的大尺寸异形铜合金厚板以便满足线圈复杂受力的要求。通过应力分析,确定了在TFC上使用的3种铜合金。介绍了大尺寸异形铜合金板材的制造工艺和铜板多项性能的测试结果,结果表明异形铜合金板材的尺寸及各项性能均满足了HL-2M装置环向场线圈的工程设计及加工要求。     

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为利于HL-2M真空室(VV)及极向场线圈(PFC)的整体安装,环向场线圈(TFC)采用比特板式结构,这种结构需要用到高强度高导电性能的大尺寸异形铜合金厚板以便满足线圈复杂受力的要求.通过应力分析,确定了在TFC上使用的3种铜合金.介绍了大尺寸异形铜合金板材的制造工艺和铜板多项性能的测试结果,结果表明异形铜合金板材的尺寸及各项性能均满足了HL-2M装置环向场线圈的工程设计及加工要求.     

The stability margin on EAST tokamak

The experimental advanced superconducting tokamak (EAST) is the first full superconducting tokamak with a D-shaped cross-sectional plasma presently in operation. Its poloidal coils are relatively far from the plasma due to the necessary thermal isolation from the superconducting magnets, which leads to relatively weaker coupling between plasma and poloidal field. This may cause more di?culties in controlling the vertical instability by using the poloidal coils. The measured growth rates of vertical stability are compared with theoretical calculations, based on a rigid plasma model. Poloidal beta and internal inductance are varied to investigate their effects on the stability margin by changing the values of parameters αn and γn(Howl et al 1992 Phys. Fluids B 4 1724), with plasma shape fixed to be a configuration with k = 1.9 and δ = 0.5. A number of ways of studying the stability margin are investigated. Among them, changing the values of parameters κ and li is shown to be the most effective way to increase the stability margin. Finally, a guideline of stability margin Ms(κ,li,A) to a new discharge scenario showing whether plasmas can be stabilized is also presented in this paper.     

HL-2A 装置的边缘参数测量

HL-2A 装置中平面边缘的等离子体特性通过磁力传动的马赫/ 雷诺协强/ 朗缪尔10 探针组进行了研究。10 探针组安装在可径向向里和向外移动, 并可绕轴旋转360^o 的传动杆上, 用于测量主等离子体边缘的温度、密度、悬浮电位、空间电位、径向和极向电场、湍流的雷诺协强、径向和极向等离子体流速及其径向分布。HL- 2A 装置的实验结果表明, 边缘等离子体扰动诱发的雷诺协强产生了边缘极向流; 雷诺协强的径向梯度驱动带状流抑制了湍流输运。     

Modelling the electric field applied to a tokamak

The vector potential for the Ohmic heating coil system of a tokamak is obtained in semi-analytical form. Comparison is made to the potential of a simple, finite solenoid. In the quasi-static limit, the time rate of change of the potential determines the induced electromotive force through the Maxwell-Lodge effect. Discussion of the gauge constraint is included.     

Reaching high poloidal beta at Greenwald density with internal transport barrier close to full noninductive current drive

In the ASDEX Upgrade tokamak, high poloidal beta up to beta(pol) = 3 at the Greenwald density with H-mode confinement has been reached. Because of the high beta, the plasma current is driven almost fully noninductively, consisting of 51% bootstrap and 43% neutral beam driven current. To reach these conditions the discharge is operated at low plasma current ( I(P) = 400 kA) and high neutral beam heating power ( P(NBI) = 10 MW). The discharge combines an edge (H mode) and internal transport barrier at high densities without confinement-limiting MHD activities. The extrapolation to higher plasma currents may offer a promising way for an advanced scenario based fusion reactor.     

HL—1装置的反磁磁通测量

本文简要地叙述了HL-1装置上等离子体反磁磁通测量,由此推算β_p、平均能量、能量约束时间的原理和方法,给出了典型放电的测量和计算结果。     

Sheared poloidal flow driven by mode conversion in tokamak plasmas

A two-dimensional integral full-wave model is used to calculate poloidal forces driven by mode conversion in tokamak plasmas. In the presence of a poloidal magnetic field, mode conversion near the ion-ion hybrid resonance is dominated by a transition from the fast magnetosonic wave to the slow ion cyclotron wave. The poloidal field generates strong variations in the parallel wave spectrum that cause wave damping in a narrow layer near the mode conversion surface. The resulting poloidal forces in this layer drive sheared poloidal flows comparable to those in direct launch ion Bernstein wave experiments.     

Magnetohydrodynamic mechanism for pedestal formation

Time-dependent two-dimensional magnetohydrodynamic simulations are carried out for tokamak plasmas with edge poloidal flow. Differently from conventional equilibrium theory, a density pedestal all around the edge is obtained when the poloidal velocity exceeds the poloidal sound speed. The outboard pedestal is induced by the transonic discontinuity, the inboard one by mass redistribution. The density pedestal follows the formation of a highly sheared flow at the transonic surface. These results may be relevant to the L-H transition and pedestal formation in high performance tokamak plasmas.     

Computational Study of MHD Equilibrium of Noncircular Tokamak Reactor Plasmas

The MHD equilibrium and stability of noncircular tokamak plasmas limited by a separatrix is studied for reactor size systems. A typical example with a plasma current of 15.8 MA and major radius of 8.1 is presented. The required vertical field is generated by a set of discrete external coils and no conducting shell is included. The detailed equilibrium shape is calculated numerically for a vertical elongated plasma with two stagnation points symmetrically located above and below the midplane as would be required for a system with a poloidal divertor. The plasma height to width ratio is 2, the plasma shape factor is 1.6 and poloidal ? is 2.2. The plasma is locally stable. The general stability criteria with respect to quasi-rigid motions (special kink modes) are calculated numerically and found to be satisfied. Size scaling and the engineering constraints are discussed.     

Study of density and potential fluctuations in the TEXT tokamakwith a heavy ion beam probe

A heavy ion beam probe was used to study the characteristics of density and potential fluctuations in the TEXT tokamak. Fluctuations of density and space potential are nearly Boltzmann like, n˜/n~φ˜/kT_e, near the edge of the plasma (0.80.9). The turbulent E&oarr;×B&oarr; radial particle flux is sufficient to account for all of the particle loss from the tokamak. No poloidal asymmetries, within a poloidal angle range of about 70°, are observed in the fluctuation levels. The fluctuation spectral shape, the density potential phase angle, and the fluctuation propagation speed show a strong radial dependence     

Investigation on the Hard X-ray Radiations of the IR-T1 Tokamak Plasma: Electric and Magnetic Perspectives

In this experiment, the effect of magnetohydrodynamic (MHD) fluctuations in the hard X-ray radiation from the IR-T1 tokamak plasma is investigated. To reach this goal, the main parameters of plasma such as plasma current and loop voltage are measured. Also, the rake and poloidal Langmuir probes are used to calculate the radial and poloidal electric fields. To detect the hard X-ray radiation, a NaI-scintillator detector is used. To study on the MHD fluctuations, an array of 12 Mirnov coils is used. The obtained data are analyzed by using the singular value decomposition (SVD) algorithm. The wavelet spectrum of the dominant principal components of Mirnov coils is drawn. The results of wavelet and SVD analysis show that the hard X-ray radiation is increased with increasing the fluctuations of the dominant principal components (at the same time). It is also shown that the rate of hard X-ray radiation emitted from the tokamak plasma increased with increasing the MHD fluctuations. The energy of the system is wasted and reduced by these radiations. This an increase in the particle pressure of the plasma.     

快加热环流器等离子体的位形演变

本文讨论了环流器等离子体在快加热过程中位形演变的近似描述问题。对两类重要的通量守恒演变系列,即绝热压缩和非压缩快加热,具体计算了平衡解。假定等离子体截面形状有任意的小变形,但初态位形只有一个椭圆磁轴,所用近似方法基于对反环径比展开。结果表明,这一方法可以成功地描述绝热压缩演变系列;对非压缩快加热,在磁轴位移不很大时,所得结果与严格的二维通量守恒解是相符的。 关键词：