检索结果-南通市图书馆

DISCUSSION ON DEFECTS DISTRIBUTION NEAR THE STEEL SURFACE IRRADIATED BY INTENSE PULSED ION BEAM

Acta Metallurgica Sinica(English Letters) 2002年第1期15卷 113-118页

作者： X.Y. Le S. Yan W.J. Zhao B.X. Han W. Xiang Institute of Heavy Ion Physics Peking University Beijing 100871 China

The surface defect distribution in stainless steel irradiated with intensepulsed ion beam (ipib) of current density above 60A/cm^2 and acceleration voltage 300-500ke V wasdiscussed and analyzed. The defects near the surface of stainless steel were generated in two ways:(1) generated by the bombardment of energetic ions and (2) induced by the high level stress near thesurface. Thus the temperature and stress distributions near the steel surface were calculated bymeans of our STEipib code, which treated with the thermal-dynamical process in the target irradiatedby the ipib. Based on these distributions, the generations and movements of these defects werediscussed and compared with the experiment results.

关键词： ipib defect coupled fluid elastoplastic equation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Numerical Simulation on Molten Process of GaAs Target Bombarded by Intense Pulsed Ion Beam

Numerical Simulation on Molten Process of GaAs Target Bombar...

引用

Fifth International Conference on Surface Engineering

作者： Jianjun Sun1 Jianfeng Li2 Zhendong Liu1 Guoqing Li1 1State Key Laboratory of Materials Modification by Laser Ion and Electron Beams School of Physics and Optoelectronic Technology Dalian University of Technology Dalian 116024 China 2 Dalian Jiaotong University Dalian 116028 China

Based on energy equation,a one-dimensional model was used for the evolution of the temperature distribution in the GaAs target bombarded by Intense Pulsed Ion Beam（ipib）.The numerical simulation was completed according to a fitting result from the waves of the ion diode magnetically insulated and the ion current density detected by Faraday cup at the focus region of the Russian TEMP type *** parameters of the ipib are:ion beam composing of H+ 70 %,C+ 30 %,with average value of pulsed voltage 300kV,the maximal peak of current density of the beam 260 A/cm2,pulsed width 60 *** GaAs chemical properties at high temperature,we created the model to describe the molten process,simulation on the GaAs speciality below the melting point,and Ga speciality above the melting point because liquid As easily *** numerical simulation results reveal the temperature distributing in the samples and provide quantitative informations of the first melting time at 10ns and melting layer thickness 2.88 μm after one pulse.

关键词： Numerical simulation ipib Temperature field GaAs

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

强流脉冲离子束辐照砷化镓温度场的数值模拟

强流脉冲离子束辐照砷化镓温度场的数值模拟

引用

作者：孙建军大连理工大学

学位级别：硕士

强流脉冲离子束因其自身的诸多优越性,在材料领域里越来越受到重视。不同能量密度的束流因与靶作用效果不同而用来进行不同的研究目的,较低的能量可以直接用于改性,较高的能量既可以用来改性又可以用来沉积薄膜及制备纳米粉。如何针对... 详细信息

强流脉冲离子束因其自身的诸多优越性,在材料领域里越来越受到重视。不同能量密度的束流因与靶作用效果不同而用来进行不同的研究目的,较低的能量可以直接用于改性,较高的能量既可以用来改性又可以用来沉积薄膜及制备纳米粉。如何针对不同的靶材控制工艺参数达到实现不同的目的,需要从理论上进行指导,不能仅凭经验确定,因而建立有效的数值方法来解决这一非线性问题是非常必要的。紧密结合我们三束材料改性国家重点实验室从俄罗斯引进的TEMP型强流脉冲离子束(ipib)加速器,根据拟合实测磁绝缘二极管(MID)电压波形以及采用法拉第筒检测的离子流密度建立了相应的物理模型,研究了ipib辐照GaAs材料的过程中,材料内部温度场的变化,通过数值模拟找到GaAs靶发生熔化和汽化的能量阈值及其在一个脉冲时间内的温度场时空变化曲线。研究了辐照过程中热力学效应,建立了烧蚀过程的一维模型,对GaAs靶的烧蚀过程进行了数值计算,得到了脉冲处理过程中靶材内部的温度场分布及其演化规律。在温度场的模拟过程中,首先通过实测数据拟合了脉冲宽度为70ns,加速电压峰值为300kV,平均脉冲束流密度为180A/cm的电压和束流密度曲线以及功率密度函数。束流成分为H70%、C30%的ipib垂直辐照GaAs材料,一个脉冲结束后,混合离子束的能量沉积深度为2.75μm左右,表面处沉积的最大能量是18.2kJ/cm左右。模拟结果给出了GaAs材料内部的温度时空分布和GaAs材料的熔化阈值为2.59kJ/cm,发生在脉冲开始后的第10ns。理论模拟结果与实验结果接近。束流中不同种类离子份额会产生不同的辐照效应。模拟研究了MID阳极采用石墨和采用聚乙烯涂层:由于碳离子入射靶材射程较短,而氢离子相对较长,因而MID采用石墨阳极时(H30%、C70%),束流能量主要沉积在表层,适用于薄膜制备的研究;而采用聚乙烯涂层时(H70%、C30%),能量沉积相对较深,适用于材料改性的研究。

关键词：数值模拟 ipib 温度场 GaAs 熔化阈值能量沉积

来源：

同方学位论文库评论