Simulation Study of IBW Heating in HT-7 Tokamak

Preliminary simulation results obtained with the code developed for ion Bernstein wave （IBW） heating in the HT-7 tokamak are presented. Comparison of the simulation of IBW heating and an HT-7 experiment confirms that using IBW of various frequencies can result in local or global plasma heating. The studies suggest that IBW absorption by ions near the ion cyclotron resonant layer and by electrons via electron Landau damping （ELD） around the maximum of n// offers a possible mechanism of plasma heating.     

HT-7低杂波相控天线阵的耦合特性分析

HT-72.45GHz低混杂波系统利用相控波导阵列将微波能量耦合到等离子体中。本工作基于二维线性耦合理论，主要利用Step+Ramp的等离子体密度剖面模型，详细分析了HT-7装置上各种关键参数(如边缘密度、密度梯度、相邻主波导相位差等)下低杂波波导阵列天线的耦合特性。分析表明，通过调节主波导之间－90°～90°的相差，天线的n_∥谱可在1.93～3.15之间灵活调节;当天线口边缘密度为0.5×10¹⁸～2×10¹⁸m^-3时，波导阵天线的反射系数可保持在5%以下，方向性系数很大;主波导之间相位差的改变对波导阵的驱动效率有很大影响。     

低杂波分段调相技术的计算机控制系统

本文主要介绍了低杂波分段调相技术的计算机控制系统的组成及工作原理。讨论了计算机偏差调节算法在本系统的应用。详细讲述了系统硬件及软件的构成，并给出了控制系统的程序框图。     

QNX系统下PXI多功能数据采集卡驱动程序开发

介绍QNX6. 20系统下设备资源管理器的运行机理和体系系统。结合PXI总线设备的体系结构,采用三级分离的方式开发PXI多功能采集卡的驱动程序。具体分析应用程序级和硬件驱动级驱动函数的开发,重点阐述系统调用级驱动函数的开发。     

Calculation of AC Losses of CICC for Superconducting Outsert Coils in a Hybrid Magnet

This paper is devoted to predict AC loss of Cable in Conduit Conductor (CICC) which is of importance in the design of conductors. The consideration for the conductor’s design and main parameters for the magnets are introduced. In order to attain a good accuracy in the calculation of AC losses, the field distribution within superconducting outsert should be considered. Calculation of the AC losses, including hysteresis losses and coupling losses, is conducted. An emphasis is put on the hysteresis loss during the ramp up of the current to the operational current (15.3 kA) and the coupling loss of the conductor in a power-down condition for insert. The results are obtained to be 74.9kJ and 950J for 40 T hybrid magnets, respectively. Based on the calculation, a brief analysis of losses effect on the conductor design and the operation of magnet is given for the purpose that the capacity of the cryogenertor can be evaluated and the stability regime can be improved in our future work on the hybrid magnets.     

Design of High-power Microwave Waveguide Divider

1. IntroductionHigh-power divider plays an important part inmany fields, such as military affairs, civil affairs, scientific research. In a longpulse tokamak plasma dis-charge, Lower Hybrid Wave (LHW) is a very effectivemeans fOr current driving. According to the con-struction plan of tokamak HT-7U, a twcrowave sys-tem fOr Lower Hybrid Current Drive (LHCD) will bebuilt up, in which a power divider is required to splitthe 100 kW microwave power at a frequency of 2.45GHz into two equal …     

Composition of HT-7 LHCD and its Protection Systems

1. IntroductionHT-7 superconducting tokamak Il] is a mediumsize experimental device for experiment and researchof nuclear fusion. A megawatt-grade lower hybridcurrent drive (LHCD) [21 system was constructed forit in 1996. The layout of HT-7 2.45 GHz LHCD sys-tem is shown in Fig.l. For a better operation of theLHW system, whose wave source mainly consists of12 klystron amplifiers, it is necessary to studied indetail the composition of HT-7 LHCD system andits protection systems.1.1 Mas…     

基于PWM变换器的长脉冲快速高压直流电源

就两种电源模式进行比较分析,并给出电磁暂态模拟仿真计算结果。从理论和模拟仿真出发验证了PWM开关电源方案的可行性。     

ECRH系统中MOD控制系统的研究

负高压电源系统是电子回旋共振加热（ECRH）系统的重要组成部分,而MOD控制系统则是负高压电源系统乃至整个ECRH系统运行的关键。介绍了系统的理论背景和工作原理,并详细阐述了该控制系统的硬件结构和软件流程。实验运行表明,该系统运行稳定、控制正确、保护迅速可靠。     

HT—7低杂波天线精确定位系统

文中主要介绍了HT-7低杂波天线精确定位系统的组成及工作原理,描述了软硬件设计的原理和过程,详细地分析了单片机高速输出端口生成周期性数字信号的原理和方法,并给出了相关程序的详细框图。