Combined effects of ambient gas pressures and magnetic field on laser plasma expansion dynamics  

作　　者：Atif HUSSAIN Xun GAO Qi LI Zuoqiang HAO Jingquan LIN Atif HUSSAIN;高勋;李奇;郝作强;林景全(School of Science, Changchun University of Science and Technology, Changchun 130022, People's Republic of China)

机构地区：School of Science, Changchun University of Science and Technology, Changchun 130022, People＇s Republic of China

出　　处：《Plasma Science and Technology》2017年第1期79-84,共6页等离子体科学和技术（英文版）

基　　金：supported by National Nature Science Foundation of China under Grant Nos.61178022 and 61575030;Research funds for the Doctoral program of Higher Education of China(No.20112216120006,20122216120009);supported by the Science and Technology Department of Changchou City(No.14KP007)

摘　　要：In this work,we investigated the influence of air gas pressures on the expansion features of nanosecond laser ablated aluminum plasma in the absence and presence of a nonuniform magnetic field using fast photography.A particular emphasis was given to the plume dynamics（shape,size） with the combined effects of ambient gas pressures and an external magnetic field.Free expansion,sharpening effect,and hemi-spherical structures of the aluminum plasma were observed without a magnetic field under different gas pressures.Analysis of the resulting plume images with the combined effects of air gas pressures and a magnetic field show significant changes,such as plume splitting,elliptical geometry changes,radial expansion,and plume confinement.Furthermore,the total size of the plasma plume with a magnetic field was measured to be smaller than the plasma plume without a magnetic field at several background pressures.In this work,we investigated the influence of air gas pressures on the expansion features of nanosecond laser ablated aluminum plasma in the absence and presence of a nonuniform magnetic field using fast photography.A particular emphasis was given to the plume dynamics（shape,size） with the combined effects of ambient gas pressures and an external magnetic field.Free expansion,sharpening effect,and hemi-spherical structures of the aluminum plasma were observed without a magnetic field under different gas pressures.Analysis of the resulting plume images with the combined effects of air gas pressures and a magnetic field show significant changes,such as plume splitting,elliptical geometry changes,radial expansion,and plume confinement.Furthermore,the total size of the plasma plume with a magnetic field was measured to be smaller than the plasma plume without a magnetic field at several background pressures.

关 键 词：magnetic field air pressure EXPANSION plume front PROPAGATION 

分 类 号：O53[理学—等离子体物理]