EAST中性束注入射频离子源放电模拟研究

中性束注入加热是核聚变中非常重要的一种辅助加热手段,离子源所能达到的性能决定了东方超环(Experimental Advanced Superconducting Tokamak, EAST)中性束注入所能达到的指标。为了实现长脉冲和高功率加热的需求,采用射频离子源取代传统的热阴极离子源已成为未来离子源发展的一种趋势。本文对射频离子源的结构设计和放电特性进行了理论模拟研究,给出了线圈匝数、匝间距、驱动器尺寸、放电气压和射频功率等参数与等离子体参数间的关系,为接下来射频离子源的研制和实验奠定一定的理论基础。     

射频负离子源数据管理系统设计

射频负离子源数据管理系统旨在管理中性束注入实验中产生的诸如信号数据、日志记录、图像记录等大量实验数据,以直观高效地展示实验运行进展。该设计选择NI(National Instruments)系列板卡实现数据采集、应用MDSplus(Model Drive System plus)的模型树和脉冲树作为存储结构、配套jScope软件实现波形绘制,解决了中性束注入系统调试运行过程中产生大量的数据管理困难问题,实现了稳态大规模数据实时处理和统一管理。     

射频负离子源分布式定时同步系统设计

为满足负离子源中性束注入系统对定时同步的功能需求,设计了射频负离子源分布式定时同步系统.通过精密时钟同步协议对中性束系统中的各子系统进行同步控制,建立统一的时钟基准.实现精准控制各子系统的投入时序以及运行时间,有效提高定时精准度,保证每炮实验完整有序进行.实验测试结果表明:目前同步控制精度控制在1 μs以下,满足时序控...     

聚变堆中性束注入系统的电偏转器概念设计

中性束注入是磁约束核聚变研究重要的辅助加热和电流驱动手段.由于负离子源中性束注入系统束能量高、束斑大,电偏转已经成为剩余离子剥离的首选方案,其剩余离子剥离设备被称为电偏转器.电偏转器作为实现束流中性化的核心设备,其性能决定了中性束注入系统的工作效率.本文提出了聚变堆主机关键系统研究中负离子源中性束注入系统电偏转器的概念...     

辐射场所钥匙管理系统设计

针对辐射场所中钥匙管理系统智能化程度较低,钥匙管理混乱难以实现高效利用,且钥匙丢失难以追溯的问题,提出了一种专门应用于辐射场所门禁中的新型智能钥匙管理系统。该系统主要由机械系统、驱动控制系统和人机交互系统组成。控制系统对检测或输入的信号进行处理并发出指令后,机械系统可以实现钥匙的精准传送,液晶显示屏可以显示取用钥匙的人员信息及钥匙取还的状态。上位机可以实现数据的接收、处理、存储和指令发送。经测试,该系统安全可靠、方便实用,能达到科学管理钥匙的目的。     

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.     

NBI综合测试台低温真空系统设计

低温真空系统是NBI综合测试台(NBITF)的一个重要子系统,它为与束的生成和传输过程相关的各类实验提供真空环境支持。在介绍NBITF基本组成的基础上,重点阐述了其低温真空系统的冷凝屏结构与布局设计、气源特性和热负荷特性,并最终讨论确定了低温真空系统的冷量供给形式。实验结果表明,该低温真空系统的设计能满足NBITF的设计使用要求,并验证了EAST-NBI低温真空系统设计的正确性。     

EAST-NBI离子源电极打火分析及处理

强流离子源是EAST(Experimental Advanced Superconducting Tokamak)中性束注入器(Neutral Beam Injector,NBI)最关键的核心部件,其能达到的性能在很大程度上决定了EAST中性束注入器所能达到的指标。离子源在束引出时电极打火现象偶有发生,这对于离子源的正常运行有非常严重的影响,甚至危害离子源的寿命。本文结合离子源运行过程中的束引出实验波形和水流量热计(Water Flow Calorimetry,WFC)系统的测量数据得出等离子体发射面的束流光学系统一直处于非最佳聚焦状态是导致打火的原因,试通过优化高压投入时刻等离子体与高压的匹配,实现高压的稳定投入有效抑制打火现象的发生,并且给离子源加入硬件保护机制,为离子源安全稳定运行奠定基础。     

Achievement of 1000 s plasma generation of RF source for neutral beam injector

A radio frequency(RF) ion source was developed for neutral beam injector in Institute of Plasma Physics, Chinese Academy of Sciences(ASIPP). A cylindrical driver based RF plasma source was tested and optimized for long pulse operation. Recently, the plasma source achieved 1000 s stable plasma discharge with RF power of 35 k W and source pressure of 0.7 Pa for the first time.The heat loading on each of driver components such as the Faraday shield(FS), RF coil and expansion chamber was measured by the water flow calorimeter system. The experiment results showed that FS is the component with highest heat loading and the heat loading on FS was about 65.8% of total heat loading on source. The details of the long pulse operation of RF plasma source are presented in this paper.     

Preliminary results of optical emission spectroscopy by line ratio method in the RF negative ion source at ASIPP

Optical emission spectroscopy (OES) using the trace rare gases of Ar and Xe have been carried out in a radio frequency (RF) driven negative ion source at Institute of Plasma Physics, Chinese Academy of Science (ASIPP), in order to determine the electron temperature and density of the hydrogen plasma. The line-ratio methods based on population models are applied to describe the radiation process of the excited state particles and establish their relations with the plasma parameters. The spectral lines from the argon and xenon excited state atoms with the wavelength of 750.4 and 828.0 nm are used to calculate the electron temperature based on the corona model. The argon ions emission lines with the wavelength of 480 and 488 nm are selected to calculate the electron density based on the collisional radiative model. OES has given the preliminary results of the electron temperature and density by varying the discharge gas pressure and RF power. According to the experimental results, the typical plasma parameters is T_e ≈ 2–4 eV and n_e ≈ 1×10 ¹⁷– 8×10¹⁷ m⁻³ in front of plasma grid.