Analysis on Pressure Distribution in HT-7 Neutral BeamInjection System

Neutral Beam Injection (NBI) is an effective way to improve the efficiency of tokamak heating system. This article primarily introduces a work on the pressure distribution inside the tank of NBI heating system, especially inside the neutralizer, which is got by selecting a proper mathematical model and constructing a series of rational calculating formulas on pressure distribution. Furthermore, we simulate the pressure distribution by the Monte Carlo method. Comparing the result of simulation with that of theoretical calculation, we find that both the results are very close each other, showing their mutual validity.     

Logical and Timing Control for Diagnostic Neutral Beam Injection on HT-7

The timing and master control logic （MCL） units are the most important function units of the diagnostic neutral beam （DNB） power supply control system. The units control the operation of nine power supply subsystems of the DNB system, and provide protection for the DNB system from faults such as beam source arc down. Based on the characteristics of the DNB power supply system, the timing and MCL units have been designed, fabricated and tested. Experiments prove that the timing unit is convenient, flexible and reliable, and the MCL is functional.     

HT-7托卡马克实验装置上基于PLC控制的中性束诊断电源系统

文章介绍HT-7托卡马克实验装置上的中性束诊断电源系统的组成、结构，以及基于S7-300PLC的逻辑控制系统。实验表明，该系统操作简单，性能稳定可靠。     

Development of Distributed Control System for Neutral Beam Injector on EAST

A distributed control system of Neutral Beam Injector(NBI) on the Experimental Advanced Superconducting Tokamak(EAST-NBI) is briefly presented in this paper.The control system is developed in accordance with the experimental operational characteristics of the EASTNBI.The NBI control system(NBICS),which is based on the computer network technologies and classified according to the control levels,consists of three levels:a remote monitoring layer,a server control layer,and a field control layer.The 3-layer architecture is capable of extending the system functions and upgrading devices.The timing system provides the reference clock of the synchronization and interlock for the EAST-NBI system.An interlock system ensures the safety of the experiment operators and field devices.Both of the ion sources of the beamline are designed to operate independently.This lays an important foundation for developing a control system for the second beamline on EAST.Experimental results demonstrate that the NBICS meets functional requirements of the EAST-NBI control,and makes experimental operations visual and automatic.     

Performance of Diagnostic Neutral Beam for the HT-7 Tokamak

Diagnostic neutral beam (DNB), combined with spectral diagnostics, is employed to measure the ion temperature in HT-7. The factors affecting the extracted beam are studied in the experiment for the high performance diagnostic neutral beam. A 6.5 A extracted hydrogen current at 43 keV of 100 ms was obtained after optimization. The extracted beam has a proton ratio as high as 40%, and can penetrate into the core plasma after neutralization to measure the ion temperature effectively.     

Experimental Study of Diagnosis Neutral Beam for HT-7 Tokamak

Parametrical effect on plasma discharge and beam extraction in the diagnosis neutral beam （DNB） system for HT-7 tokamak was studied experimentally. Useful results with an improved beam quality were obtained.     

HT-7 诊断中性束电源控制系统设计

本文介绍了HT-7托卡马克实验装置上研制的基于脉宽调制（PWM）的诊断中性束电源系统的组成、结构和控制需求,以及控制系统的组成和控制功能等。经实际调试与多轮HT-7实验运行,验证了该套电源控制系统的稳定性与可靠性。     

诊断中性束电源的数据采集与处理系统

文中介绍了一种用于诊断中性束电源系统的数据采集与处理系统(DPAS).在电源系统的运行过程中,系统需要对18路电流/电压信号进行实时采集.DPAS采用网络技术以客户端/服务器模式进行开发.系统引进了一种高效的压缩算法从而大量地节约了数据存储所需的磁盘空间.系统所采用的数据存储格式与EastScope软件(一款用于查看实验数据的软件)兼容,从而使实验操作人员可以很容易对实验结果进行分析和总结.     

全超导非圆截面托卡马克中性束注入窗口材料活化研究

中性束注入加热为全超导非圆截面托卡马克(EAST)主要辅助加热方式之一.伴随着中性束注入加热,等离子体中子出射强度可达到1014 n/s.由于中性束注入窗口具有较大的开口尺寸,窗口泄露的大量中子可能影响系统的安全稳定运行.本文基于EAST中性束二维模型和蒙特卡洛程序MCNP与材料活化程序FISPACT,研究EAST两条...     

Numerical Calculation of the Attenuation of Neutral Beam Injection on HL-2A

The arrangement of the neutral beam line in HL-2A tokamak is introduced. Attenuation of neutral beam injection is analyzed numerically under different plasma conditions： different plasma densities, beam energies, electron temperatures, and impurity concentrations. Both optimized plasma density and beam energy for plasma heating are obtained.     

基于超级电容储能的中性束注入系统弧电源设计

弧电源是中性束注入加热系统中最关键的设备之一,它的性能决定了弧放电的稳定性及束流引出的品质。为提高弧放电稳定性,降低电网容量,减少对电网的冲击,弧电源拓扑设计采用了基于超级电容储能和开关电源技术的DC/DC变换器结构。利用多个IGBT功率模块并联工作,可提高电源工作频率,实现更快的动态响应速度。在详细分析电源工作过程的基础上,设计了滤波电路和电流快速转移电路,根据电源的要求和具体参数,由一阶RL电路的电流响应特性,精确计算出滤波电感的最小值。最后,利用Matlab对电源性能指标进行了仿真验证,结果表明电源性能完全符合设计要求。     

中性束注入快离子初始分布的蒙特卡罗模拟

比较精确地模拟计算中性束注入（NBI）托卡马克等离子体的快离子初始分布是采用大规模数值模拟方法研究NBI快离子相关物理问题的首要任务。本文建立了NBI托卡马克等离子体的简化物理模型,采用蒙特卡罗方法自主开发了NBI应用程序。选取ASDEX Upgrade（AUG）托卡马克上切向注入和垂直注入两种情况为计算实例,分别模拟计算出NBI粒子被离子化的初始三维空间位置,并统计得出初始快离子的径向分布、极向角分布、环向角分布和投掷角分布,这些计算结果与国际上相关文献结果一致。     

Alternate Data Acquisition and Real-time Monitoring System on HT-7 Tokamak

1 Introduction There are many tokamak devices over the world. Be- cause the tokamak device is based on the principle of a transformer, almost all tokamaks are pulse-operated and most of their discharge duration is within one or two minutes. A conventional data acquisition and anal- ysis system would be good enough for such devices. However, recent lower hybrid current-drive (LHCD) ex- periments such as those on the HT-7 and Tore Supra have generated discharges lasting several hundred sec- …     

Calculation of Beam Intensity Distribution for the Neutral Beam Injection in EAST

Theoretical beam intensity distribution is derived for the neutral-beam-injection ion source with a multi-slot extraction in EAST. The beam intensity profile, b...     

Numerical Simulation of Subcooled Boiling Inside High-Heat-Flux Component with Swirl Tube in Neutral Beam Injection System

In order to realize steady-state operation of the neutral beam injection（NBI） system with high beam energy,an accurate thermal analysis and a prediction about working conditions of heat-removal structures inside high-heat-flux（HHF） components in the system are key issues.In this paper,taking the HHF ion dump with swirl tubes in NBI system as an example,an accurate thermal dynamic simulation method based on computational fluid dynamics（CFD） and the finite volume method is presented to predict performance of the HHF component.In this simulation method,the Eulerian multiphase method together with some empirical corrections about the inter-phase transfer model and the wall heat flux partitioning model are considered to describe the subcooled boiling.The reliability of the proposed method is validated by an experimental example with subcooled boiling inside swirl tube.The proposed method provides an important tool for the refined thermal and flow dynamic analysis of HHF components,and can be extended to study the thermal design of other complex HHF engineering structures in a straightforward way.The simulation results also verify that the swirl tube is a promising heat removing structure for the HHF components of the NBI system.     

Stable Spheromaks Sustained by Neutral Beam Injection

It is shown that spheromak equilibria, stable at zero-beta but departing from the Taylor state, could be sustained by non-inductive current drive at acceptable power levels. Stability to both ideal MHD and tearing modes is verified using the NIMROD code for linear stability analysis. Non-linear NIMROD calculations with non-inductive current drive and pressure effects could point the way to improved fusion reactors.     

Ignition Approach by Neutral Beam Injection Heating in Impurity Contaminated Tokamak Reactors

Available heating power by neutral beam injection in a tokamak reactor is evaluated semi-empirically. Using this estimated value, device and plasma parameters to ignite the plasma in impurity contaminated tokamak reactors are investigated. By lowering the plasma density and concurrently by enlarging the plasma minor radius or aspect ratio, the difficulty of NBI heating can be avoided, and the ignition is almost always possible both for trapped ion mode and Alcator scaling laws.     

中性束注入器水流热量计系统优化分析

介绍了用于计算中性束注入实验中束流功率沉积的水流热量计系统优化及优化后的测试结果。前期的水流热量计系统利用串口传输和分散式牛顿模块采集,采样率低、传输速度慢、抗干扰能力差、无法满足实验要求;优化后的系统基于虚拟仪器,采用TCP\IP协议传输和虚拟仪器技术,提高了系统的采样率和精度、优化了数据传输速度及抗干扰能力。优化后的系统经测试可以准确监测中性束注入器装置上各热承载部件冷却水的温升及流量,并分析得到中性束注入时束流在各热承载部件上的功率沉积。实验结果表明优化后的系统工作稳定,使用灵活,数据准确,满足实验要求。     

Remote Control for the HT-7 Distributed Data Acquisition System

HT-7 is the first superconducting tokamak device for fusion research in China. Many experiments have been done in the machine since 1994, and lots of satisfactory results have been achieved in the fusion research field on HT-7 tokamak^[1]. With the development of fusion research, remote control of experiment becomes more and more important to improve experimental efficiency and expand research results. This paper will describe a RCS (Remote Control System),the combined model of Browser/Server and Client/Server, based on Internet of HT-7 distributed data acquisition system (HT7DAS). By means of RCS, authorized users all over the world can control and configure HT7DAS remotely. The RCS is designed to improve the flexibility, opening, reliability and efficiency of HT7DAS. In the paper, the whole process of design along with implementation of the system and some key items are discussed in detail. The System has been successfully operated during HT-7 experiment in 2002 campaign period.     

Design of the Prototype Negative Ion Source for Neutral Beam Injector at ASIPP

In order to support the design,manufacture and commissioning of the negativeion-based neutral beam injection(NBI) system for the Chinese Fusion Engineering Test Reactor(CFETR),the Hefei utility negative ion test equipment with RF source(HUNTER) was proposed at ASIPP.A prototype negative ion source will be developed at first.The main bodies of plasma source and accelerator of the prototype negative ion source are similar to that of the ion source for EAST-NBI.But instead of the filament-arc driver,an RF driver is adopted for the prototype negative ion source to fulfill the requirement of long pulse operation.A cesium seeding system and a magnetic filter are added for enhancing the negative ion density near the plasma grid and minimizing co-extracted electrons.Besides,an ITER-like extraction system is applied inside the accelerator,where the negative ion beam is extracted and accelerated up to 50 kV.