Expansion of Plasma of Electrically Exploding Single Copper Wire Under 4.5kA～9.5kA/Wire

Abstract The experimental system for electrically exploding single metal wire has been de-signed and manufactured. Expansion of the dense plasma column formed from an electricallyexploding Cu wire of diameter 30 μm has been studied with a high-speed photographer to obtainthe time-dependent radius (R-t) curve. The experimental results demonstrate that the mean ex-pansion rate of the dense plasma column is 1.94 μm/ns, 2.6 μm/ns and 3.75 μm/ns according tothe peak pulse current 4.5 kA, 7 kA and 9.5 kA respectively. The results can be beneficial to givinga profound understanding of the early stage of wire-array Z-pinch physics and to improvement ontheir design.     

The Experiment of Obtaining Micron Beam in the Single-Particle Microbeam Facility of the Institute of Plasma Physics

The Experiments, methods and results of obtaining micron beam in the Microbeam Facility of the Institute of Plasma Physics were discussed in this paper. The H2^ beam was accelerated by the Van de Graa/f electrostatic accelerator, and the collimator at the end of the beam line is a 60μm thick stainless steel chip. And as a result, particle tracks on the solid track probes (CR39 film) etched in the solution of NaOH showed that the beam can go through the collimator with a small aperure (2000, 300, 55, 30, or 10μm) and 3.5μm thick vacuum film(Mylar). Besides the CR39 method, the beam was measured by an energy spectrum detector after the 10μm diameter aperture and the 3.5 μm thick vacuum film too.     

Flow Simulation and Optimization of Plasma Reactors for Coal Gasification

This paper reports a 3-d numerical simulation system to analyze the complicated flow in plasma reactors for coal gasification, which involve complex chemical reaction, two-phase flow and plasma effect. On the basis of analytic results, the distribution of the density, tempera-ture and components‘ concentration are obtained and a different plasma reactor configuration is proposed to optimize the flow parameters. The numerical simulation results show an improved conversion ratio of the coal gasification. Different kinds of chemical reaction models are used to simulate the complex flow inside the reactor. It can be concluded that the numerical simulation system can be very useful for the design and optimization of the plasma reactor.     

Neutronic Comparison of Tritium－Breeding Performance of Candidate Tritium－Breeding Materials

Tritium self-sustainment, which will meet the fuel requirement of fusion reactor, is one of the key issues of fusion power development. The tritium breeding performances of various tritium-breeding materials are compared based on a series of neutronics calculations using three-dimensional Monte Carlo neutron-photon transport code MCNP/4C with the IAEA FENDL-2 data library. The effects of the dimensions of the tritium-breeding zone and the enrichment of 6Li on Tritium Breeding Ratio (TBR) are analyzed. The effects of Be as a neutron multiplier on TBR are also calculated.     

HL-2A Tokamak Edge Modeling with B2

The outer divertor plasma of HL-2A and its associated scrape-off plasma have been simulated using a two-dimensional multi-species fluid code of Braams with a simplified neutral gas model. HL-2A has a double-null closed divertor in separate divertor chambers above and below the nearly circular plasma tours. The computed numerical grid is developed according to an ideal magnetic surface. The calculation is involved only with pure hydrogen plasma. The emphasis has been focused on parametric studies involving variation of the assumptions made for the core plasma. The peak temperatures and the heat flux near the target are of the principal concern。     

永磁材料的发展趋势

永磁材料的发展先后经历了金属永磁材料，铁氧体永磁材料，稀土永磁材料，纳米结构永磁材料等几个发展阶段，超导永磁体则是学术界近年来提出的一种新概念永磁体，本文在对永磁材料的发展历史和发展趋势进行了综合分析之后，对永磁材料今后的发展做出了预测。     

热处理温度对NiFe2O4纳米粉末红外特性及磁性能的影响

采用溶胶—凝胶法制各了NiFeO4纳米粉末，并经不同温度处理。测定了样品的X射线衍射谱、红外漫反射光谱和磁性能。结果表明，200℃以上的热处理开始促进粉末的长大和晶化过程，而互随着温度的升高，晶化程度增强，粉末粒径增大。红外漫反射谱可以较好地反映粉末的尺寸效应和形态效应，粉末粒径越小，漫反射函数值越大；当粒径达到一定尺寸时，红外漫反射的尺寸效应和形态效应消失。NiFe2O4纳米粉末的磁性能与热处理温度及粉末的粒径大小有看十分密切的关系。     

平面薄膜电感的研究与开发现状

为满足电子系统的表面贴装技术、微组装技术发展的需要，对器件片式化、小型化、微型化的要求越来越高。而电感作为电路的三大基础性元件之一，其片式化、薄膜化势在必行。本文就近几年国内外片式薄膜电感的发展研究状况做一综述。     

生坯密度对烧结Nd-Fe-B磁体微结构与磁性能的影响

结合国内烧结Nd—Fe—B磁体工业生产过程，研究了压制成型生坯密度对烧结Nd—Fe—B磁体致密化程度，显微组织、取向度及磁性能的影响。实验结果表明，生坯密度的提高可促进烧结致密化过程，抑制烧结过程晶粒的不均匀长大，提高取向度，改善磁性能。     

CXG-1型磁选装置的研制及应用

为满足环境磁学研究、陶瓷和塑料等对原料中磁性杂质的要求，研制了一种自动化程度高、效率高、磁选效果佳的CXG-I型磁选装置。该装置的磁路设计独特，当待选的原材料(浆料、粉末．沉积物等)沿该装置内置与外露的工作磁路流动时，永磁体的强磁场从各个方向将MnO-Fe2O3、Fe3O4和Fe屑等有效地吸附在其表面，由自动冲洗装置把它们清徐。其磁选纯度达到99．92—99．96％，能保证原材料的单纯性，该装置具有多用途、适宜各种场合、节省经费开支等特点，有极大的应用前景。