Spectroscopic investigations of a cathode fall region of the Grimm-type glow discharge
Spectroscopic investigations of a cathode fall region of the Grimm-type glow discharge
复制标题
格林型辉光放电阴极降落区的光谱研究
DOI：
10.1016/s0584-8547(96)01533-9
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
M. Kuraica
中科院分区：
文献类型：
--
作者：
I. Videnović;N. Konjević;M. Kuraica
本文介绍了平面阴极Grimm型辉光放电在纯氢和含少量氢的氩气中阴极区的光谱研究结果。与氩-氢混合物中的放电相比，纯氢放电的伏安特性显示出异常辉光到电弧转变的最大典型值。V-A曲线中的这个最大值在此被解释为由于阴极材料的自溅射在维持较高电流下的放电中的增加的作用。对于在阴极下降区的电场的测量，氢巴耳末线的斯塔克光谱。用Hβ和Hγ记录纯氢放电，得到了一致的结果。应用斯塔克光谱诊断格林辉光放电所固有的空间不均匀电场的一些困难进行了详细讨论。实验结果被用来测试在阴极下降区的电场分布的理论预测。理论和实验之间的合理协议的报告。多普勒光谱相同的巴耳末线被用来确定在放电中的激发氢原子的能量。在纯氢放电的阴极下降区，检测到两组激发原子：“慢”，在3.4-8.2 eV的范围内，和“快”，在80-190 eV的范围内。确定了阴极下降区中“慢”和“快”激发氢原子的相对浓度。此外，氢原子的相对浓度与温度约0.1 eV，激发在负辉光区的等离子体中，也被确定。这些“慢”和“快”氢原子的起源分别与H+和H3+离子的存在有关。在氩-氢混合物放电的阴极下降区，仅检测到能量为32-43 eV的激发氢中性粒子。它们的起源与H3+离子在这种放电中的主导作用有关。对于这两种气体，在负辉光区，在激发氢原子的温度的增加被检测到，并解释了额外的激发高能中性粒子与电子碰撞。与其他原子和离子谱线相比，氢的巴耳末谱线的轴向强度分布具有不同的形状，在阴极表面附近具有最大值。这些形状的解释反射高能中性原子与基质气体碰撞的激发。
This paper presents the results of the spectroscopic study of the cathode fall region of a plane cathode Grimm-type glow discharge in pure hydrogen and in argon with small admixtures of hydrogen. In contrast with the discharge in an argon-hydrogen mixture, the volt-ampere characteristics of the pure hydrogen discharge show a maximum typical for an abnormal glow-to-arc transition. This maximum in the V-A curve is explained here as being due to the increasing role of self-sputtering of the cathode material in sustaining the discharge at higher currents. For the measurements of the electric fields in the cathode fall region, Stark spectroscopy of the hydrogen Balmer lines is employed. Consistent results were obtained from Hβand Hγrecordings in a pure hydrogen discharge. Some of the difficulties in applying Stark spectroscopy for the diagnostics of a spatially inhomogeneous electric field inherent to Grimm glow discharges are discussed in detail. The experimental results are used to test the theoretical predictions of the electric field distribution in the cathode fall region. Reasonable agreement between theories and experiment is reported. Doppler spectroscopy of the same Balmer lines is used to determine the energies of the excited hydrogen atoms in the discharge. In the cathode fall region of a pure hydrogen discharge, two groups of excited atoms are detected: “slow”, in the range 3.4–8.2 eV, and “fast”, in the range 80–190 eV. The relative concentrations of “slow” and “fast” excited hydrogen atoms in the cathode fall region are determined. In addition, the relative concentration of hydrogen atoms with temperatures around 0.1 eV, excited in the plasma of the negative glow region, is also determined. The origin of these “slow” and “fast” hydrogen atoms is related to the presence of H+and H3+ions, respectively. In the cathode fall region of an argon-hydrogen mixture discharge, only excited hydrogen neutrals with energies of 32–43 eV are detected. Their origin is related to the dominant role of H3+ions in this discharge. For both gases, in the negative glow region, an increase in the temperature of excited hydrogen atoms is detected, and is explained by the additional excitation of energetic neutrals in collisions with electrons. The axial intensity distributions of the hydrogen Balmer lines, in comparison with other atomic and ionic lines, show different shapes with maxima in the vicinity of the cathode surface. These shapes are explained by the excitation of reflected high-energy neutral atoms in collisions with the matrix gas.