短管螺旋波放电中等离子体参数测量和模式转化研究

Characterization of plasma in a short-tube helicon source

对长度为45 cm的短放电管螺旋波放电等离子体进行了Langmuir探针、原子发射光谱以及集成电荷耦合检测器(ICCD)检测诊断,研究螺旋波等离子体的放电特性.Langmuir探针数据显示电子密度在射频功率增加过程中出现两次大幅增长,由此确认了放电模式的转换及螺旋波放电模式的出现.发射光谱测量结果与Langmuir探针测量的电子密度数据一致,发现Ar原子和Ar离子的谱线强度与放电模式变化有着密切相关性.而通过对不同放电模式的ICCD测量,获得射频功率吸收因放电模式转变而变化的方式,认为放电模式转换时电子行为和能量传递方式也发生着变化.

Characteristics of helicon plasma in a 45 cm long discharge tube were diagnosed by the Langmuir electrostatic probe,optical emission spectroscopy（OES）, and integrated capacitively coupled detector（ICCD）. The discharge in helical wave mode was confirmed by the sharply variation of electron density and electron temperature based on the Langmuir data.We have noticed that the variation of electron density measured by the Langmuir electrostatic-probe is consistent with the OES measurement. Intensities in the spectra of argon atoms and ions are strongly related to discharge modes. The photos taken by ICCD can distinguish the discharge modes in the radial region. Intensity changes in the radial region reflect the electron motivation and the energy transfer path in the helicon plasma.