Parametric scaling of neutral and ion excited state densities in an argon helicon source
Parametric scaling of neutral and ion excited state densities in an argon helicon source
复制标题
氩螺旋源中中性和离子激发态密度的参数缩放
DOI：
10.1088/0963-0252/25/2/025001
复制
发表时间：
2016
影响因子：
3.8
通讯作者：
E. Scime
中科院分区：
文献类型：
--
作者：
D. McCarren;E. Scime
我们报告了氩螺旋源中离子和中性激发态的绝对密度和温度的测量。激发离子态密度取决于离子密度、电子密度和电子温度，随着源中磁场的增加而急剧增加。中性氩亚稳态密度测量与随着磁场强度增加而增加的电离分数一致。离子温度没有显示出加热随磁场强度增加而增加的证据（仅在以接近较低混合频率的驱动频率工作的螺旋源中观察到）。测量结果是通过腔衰荡光谱法获得的，这种测量技术不需要目标激发态处于亚稳态或荧光方案的一部分；因此适用于等离子体中任何激光可到达的原子或离子跃迁。
We report measurements of the absolute density and temperature of ion and neutral excited states in an argon helicon source. The excited ion state density, which depends on ion density, electron density, and electron temperature, increases sharply with increasing magnetic field in the source. The neutral argon metastable density measurements are consistent with an increasing ionization fraction with increasing magnetic field strength. The ion temperature shows no evidence of increased heating with increasing magnetic field strength (which has only been observed in helicon sources operating at driving frequencies close to the lower hybrid frequency). The measurements were obtained through cavity ring down spectroscopy, a measurement technique that does not require the target excited state to be metastable or part of a fluorescence scheme; and is therefore applicable to any laser accessible atomic or ionic transition in a plasma.