Effect of neutral pressure on the blue core in Ar helicon plasma under an inhomogeneous magnetic field  

作　　者：王陈文 刘洋 孙萌 张天亮 谢俊发 陈强 张海宝 Chenwen WANG;Yang LIU;Meng SUN;Tianliang ZHANG;Junfa XIE;Qiang CHEN;Haibao ZHANG(Laboratory of Plasma Physics and Materials,Beijing Institute of Graphic Communication,Beijing 102600,People’s Republic of China;School of Physics,Beijing Institute of Technology,Beijing 100081,People’s Republic of China)

机构地区：[1]Laboratory of Plasma Physics and Materials,Beijing Institute of Graphic Communication,Beijing 102600,People’s Republic of China [2]School of Physics,Beijing Institute of Technology,Beijing 100081,People’s Republic of China

出　　处：《Plasma Science and Technology》2023年第4期93-100,共8页等离子体科学和技术（英文版）

基　　金：supported by National Natural Science Foundation of China(Nos.11505013 and 11875090);Beijing Municipal Natural Science Foundation(No.1192008);Beijing Municipal Commission of Education(Nos.KM202010015003,22150122029,and 202210015017)。

摘　　要：The effect of neutral pressure on the blue core in Ar helicon plasma under an inhomogeneous magnetic field was investigated in this work.The neutral pressure was set to 0.08 Pa,0.36 Pa,and 0.68 Pa.A Nikon camera,intensified charge-coupled device(ICCD),optical emission spectrometer(OES),and Langmuir probe were used to diagnose the blue core in helicon plasma.Helicon plasma discharges experienced density jumps from the E mode,H mode to W mode before power just rose to 200 W.The plasma density increased and maintained a central peak with the increase of neutral pressure.However,the brightness of the blue core gradually decreased.It is demonstrated that the relative intensity of Ar II spectral lines and the ionization rate in the central area were reduced.Radial electron temperature profiles were flattened and became hollow as neutral pressure increased.It is demonstrated that increasing the neutral pressure weakened the central heating efficiency dominated by the helicon wave and strengthened the edge heating efficiency governed by the TG wave and skin effect.Therefore,the present experiment successfully reveals how the neutral pressure affects the heating mechanism of helicon plasma in an inhomogeneous magnetic field.

关 键 词：helicon plasma blue core neutral pressure heating mechanism edge heating 

分 类 号：O53[理学—等离子体物理]