...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Physics, D. Applied Physics: A Europhysics Journal >Investigation of discharge mechanisms in helium plasma jet at atmospheric pressure by laser spectroscopic measurements
【24h】

Investigation of discharge mechanisms in helium plasma jet at atmospheric pressure by laser spectroscopic measurements

机译：大气压氦等离子体射流放电机理的激光光谱测量研究

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

We have measured spatiotemporal structures of excited species by laser spectroscopic methods in a plasma jet, which was driven by a bipolar impulse voltage pulse train of the order of kilohertz repetition rate applied across a pair of electrodes wrapped around a glass tube with a helium gas flow. We noticed the differences between the positive and the negative phases of the voltage applied to the front-side electrode placed closer to the tube exit while the back-side electrode was grounded. The experimental results showed that the radial distribution of the excited species had a hollow shape at the centre in the positive voltage phase, while it had a more uniform shape in the negative phase. The peak density of the helium metastable atom in the positive phase was almost constant irrespective of the peak applied voltage. However, it increased with the increase in the peak applied voltage in the negative phase. The mechanism causing these differences was argued from the respects of positive and negative corona discharges. We have also investigated the property of the plasma plume under conditions similar to material processing with a conductive substrate placed in front of the plasma jet. In this case, the plasma production by electron impact ionization became dominant near the substrate as was revealed from the spatiotemporal distributions of helium metastable atom and nitrogen ion densities.
机译：我们已经在等离子体射流中通过激光光谱方法测量了激发物质的时空结构，该等离子体射流是由双极脉冲电压脉冲序列驱动的，该脉冲序列的千赫兹重复频率施加在包裹有玻璃管的一对电极上，氦气气流包裹在一对电极上。我们注意到，在将背面电极接地的同时，施加到放置在靠近管出口的正面电极的电压的正相和负相之间的差异。实验结果表明，受激物种的径向分布在正电压阶段的中心呈空心形状，而在负电压阶段的形状更为均匀。正极上的亚稳态氦原子的峰值密度几乎恒定，与峰值施加电压无关。但是，它随着负相中峰值施加电压的增加而增加。从正负电晕放电的方面对引起这些差异的机理进行了争论。我们还研究了在类似于材料处理的条件下等离子羽流的特性，该条件是将材料置于等离子流的前面进行处理。在这种情况下，通过电子碰撞电离产生的等离子体在基板附近占主导地位，这从氦亚稳原子和氮离子密度的时空分布可以看出。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号