We present in this paper the comparison of an electric double layer(DL)in argon helicon plasma and magnetized direct current(DC)discharge plasma.DL in high-density argon helicon plasma of 13.56 MHz RF discharge was in...We present in this paper the comparison of an electric double layer(DL)in argon helicon plasma and magnetized direct current(DC)discharge plasma.DL in high-density argon helicon plasma of 13.56 MHz RF discharge was investigated experimentally by a floating electrostatic probe and local optical emission spectroscopy(LOES).The DL characteristics at different operating parameters,including RF power(300-1500 W),tube diameter(8-60 mm),and external magnetic field(0-300 G),were measured.For comparison,DL in magnetized plasma channel of a DC discharge under different conditions was also measured experimentally.The results show that in both cases,DL appears in a divergent magnetic field where the magnetic field gradient is the largest and when the plasma density is sufficiently high.DL strength(or potential drop of DL)increases with the magnetic field in two different structures.It is suggested that the electric DL should be a common phenomenon in dense plasma under a gradient external magnetic field.DL in magnetized plasmas can be controlled properly by magnetic field structure and discharge mode(hence the plasma density).展开更多
基金supported by National Natural Science Foundation of China(No.11975047)。
文摘We present in this paper the comparison of an electric double layer(DL)in argon helicon plasma and magnetized direct current(DC)discharge plasma.DL in high-density argon helicon plasma of 13.56 MHz RF discharge was investigated experimentally by a floating electrostatic probe and local optical emission spectroscopy(LOES).The DL characteristics at different operating parameters,including RF power(300-1500 W),tube diameter(8-60 mm),and external magnetic field(0-300 G),were measured.For comparison,DL in magnetized plasma channel of a DC discharge under different conditions was also measured experimentally.The results show that in both cases,DL appears in a divergent magnetic field where the magnetic field gradient is the largest and when the plasma density is sufficiently high.DL strength(or potential drop of DL)increases with the magnetic field in two different structures.It is suggested that the electric DL should be a common phenomenon in dense plasma under a gradient external magnetic field.DL in magnetized plasmas can be controlled properly by magnetic field structure and discharge mode(hence the plasma density).
