共查询到20条相似文献,搜索用时 15 毫秒
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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. 相似文献
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NI Qionglin FAN Tieshuan ZHANG Xing ZHANG Cheng REN Qilong HU Chundong 《等离子体科学和技术》2010,12(6):661-667
A predictive calculation is carried out for neutral beam heating of fusion plasmas in EAST by using NUBEAM code under certain plasma conditions. Results calculated are analyzed for different plasma parameters. Relations between major plasma parameters, such as density and temperature, are obtained and key physical processes in the neutral beam heating, including beam power deposition, trapped fraction, heating efficiency, and power loss, are simulated. Other physical processes, such as current-drive, toroidal rotation and neutron emission, are also discussed. 相似文献
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《等离子体科学和技术》2015,17(7):601-606
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. 相似文献
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HU Chundong 《等离子体科学和技术》2013,15(3):201-203
Neutral beam injection (NBI) is recognized as one of the most e®ective means for plasma heating. A 100 s long pulse neutral beam with 30 keV beam energy, 10 A beam current and a 100 s long pulse modulating neutral beam with 50 keV beam energy, 16 A beam current were achieved in the EAST neutral beam injector on the test-stand. The preliminary results suggest that EAST-NBI system initially possess the ability of long pulse beam extraction. 相似文献
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《等离子体科学和技术》2015,17(7):545-551
Toroidal rotation has been recognized to have significant effects on the transport and magnetohydrodynarnic(MHD) stability of tokamak plasmas.Neutral beam injection(NBI) is the most effective rotation generation method on current,tokamak devices.To estimate the effective injected torque of the first neutral beam injection system on EAST,a simplified analytic method was derived.Calculated beam torque values were validated by those obtained from the NUBEAM code simulation.According to the results,for the collisional torque,the effective tangential radius for torque deposition is close to the beam tangency major radius.However,due to the dielectric property of tokamak plasma,the equivalent tangency major radius of the J×B torque is equal to the average major radius of the magnetic flux surface.The results will be useful for the research of toroidal momentum confinement and the experimental analysis of momentum transport related with NBI on EAST. 相似文献
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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. 相似文献
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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. 相似文献
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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。 相似文献
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Distributed thermocouple measurement will be used on EAST neutral beam injection beam angular divergence measurement. In order
to determine the pulse duration of neutral beam extraction, the plates of calorimeter are analyzed by using heat transfer
science. Mathematic derivations and the results are given according to the installation location of thermocouple in the plate.
Those results could point the way to beam angular divergence measurement of EAST neutral beam injection. 相似文献
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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。 相似文献
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Neutral Beam Injection control system (NBICS) is constructed to measure the plasma current, Magnet current, vacuum pressure, cryopump temperature, control water cooling, filament voltage, and power supply, etc. The NBICS, consisting mainly of a Programmable Logic Controller (PLC) subsystem, data acquisition and processing subsystem and cryopump and vacuum pressure monitoring subsystem, has successfully been used on a NBI device. In this article, the design of NBICS on HT-7 is discussed and each subsystem is described in particular.In addition, some experimental results are reported which are very important data for further research related to the HT-7 tokamak. 相似文献
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Neutral beam injection (NBI) system with two neutral beam injections will be constructed on the Experimental Advanced Superconducting Tokamak (EAST) in two stages for high power auxiliary plasmas heating and non-inductive current drive. Each NBI can deliver 2~4 MW beam power with 50~80 keV beam energy in 10~100s pulse length. Each elements of the NBI system are presented in this contribution. 相似文献
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Yongjian Xu Chundong Hu Yuanlai Xie Lizhen Liang Jun Li Ling Yu 《Journal of Fusion Energy》2011,30(1):94-98
Distributed thermocouple measurement will be used on EAST neutral beam injection beam angular divergence measurement. In order
to obtain calculation model of beam angular divergence: (1) the structure of accelerating electrodes are analyzed, (2) mathematic
derivations of beam intensity distribution for neutral beam is given basing on theory of Gaussian distribution, (3) the processing
method of experiment data and selection of algorithm are given. The model could point the way to beam angular divergence measurement
of EAST neutral beam injection. 相似文献
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《等离子体科学和技术》2016,18(11):1139-1142
Neutral beam injection heating is one of the main auxiliary heating methods in controllable nuclear fusion research. In the EAST neutral beam injector, a water flow calorimetry(WFC) system is applied to measure the heat load on the electrode system of the ion source and the heat loading components of the beamline. Due to the heat loss in the return water pipe, there are some measuring errors for the current WFC system. In this paper, the errors were measured experimentally and analyzed theoretically, which lay a basis for the exact calculation of beam power deposition distribution and neutralization efficiency. 相似文献
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Yongjian Xu Chundong Hu Yuanlai Xie Zhimin Liu Yahong Xie Lizhen Liang Ling Yu 《Journal of Fusion Energy》2011,30(4):347-351
Beam power measurement usually adopts water flow calorimetry (WFC) for neutral beam injector. In this article a calculation
model of beam power for EAST neutral beam injector was given basing on thermocouples installed in the calorimeter plate. In
order to obtain calculation model: (1) the heat flux of the surface of beam stopping elements was calculated using heat transfer
science, (2) the processing method of data obtained from the thermocouple was given, (3) mathematic derivations of beam power
is given basing on theory of Gaussian distribution. The model could point another way to beam power measurement of EAST neutral
beam injector besides WFC. 相似文献
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《Journal of Nuclear Science and Technology》2013,50(5):305-315
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. 相似文献
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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. 相似文献