Helium In Tungsten Diffusion Behavior In Different Surface Orientation Of The Molecular Dynamics Simulation Study

Tungsten materials as possesses the advantages of high temperature resistance,corrosion resistance,has been chosen for nuclear reactor of plasma facing materials.Because tungsten material need to bear the helium plasma irradiation of high flux,tungsten material surface usually have bubbles,villous structure,pore surface morphology change phenomenon.The surface morphology changes with the change of the thermal and mechanical properties of material surface,and will be accompanied by impurities,dirt and other produce,this will become the pollution and destruction of plasma for plasma equilibrium.Therefore,helium in tungsten materials on the surface of the diffusion behavior has been related attaches great importance to scientific research personnel,respectively from the aspects of experimental and theoretical aspects also do a lot of research work.Factors affecting the spread of helium in tungsten material has a lot of,such as temperature,pressure,the surface orientation of tungsten materials and so on.Often,after entering the tungsten helium,transport and diffusion phase through these two links.Helium helium atoms in the spread of tungsten material is divided into single and multiple helium atoms.Prior to this,the relevant personnel have been the situation of other surface orientation of tungsten materials research,but still need further data as a supplement,can make the research more deeply.This paper studies the single near the surface of the helium atoms in tungsten materials,different surface orientation and the diffusion behavior of different temperatures.We will focus on observation of helium atoms in tungsten materials under different temperature,orientation,{211},and {311}orientation on the diffusion behavior,and statistical helium atoms to escape the surface of tungsten materials,and using statistical figure to summarize,the specific results are as follows.Through the analysis we found that the {211}and {311} is the difference between the two surface orientation,{211} direction only after 400 k and temperature higher than 400 k can be observed that the accumulation of helium atom,while {311} direction every temperature can be observed in the simulation.It also led to a number of helium atom escape we observed with the change of temperature of the image is different,{211} direction at 1200 k escape of the helium atom number has reached the peak,and {311} direction is proportional to the relationship between;{211} direction on the surface of the tungsten internal potential energy and potential energy difference and the direction of {311} also has difference,{311} direction difference is bigger.Direction is the same,{211}and {311},the location of the helium atoms are easy to be trapped,deeper gradually along with the rise of temperature,such as 400 k,are easy to be trapped under the second layer on the surface of tungsten materials,while about 2000 k on the fourth floor,near the phenomenon has not been summarized in the previous studies,it is because they have no simulation of high temperature conditions.In this paper,the research for the future research in the helium diffusion behavior oftungsten materials provides more surface orientation,for subsequent working to build a more perfect simulation.There is,however,the helium atoms in the tungsten materials concrete spread form,with the corresponding energy,etc.,still need to be further research.