Bohm Criterion for Collisionless Sheaths in Two-Ion-Species Plasmas

• 作者: 欧靖 胡业民 项农
• 来源期刊: 等离子体科学和技术：英文版
• 学科: 物理学
• 关键词: 等离子体鞘 物种 碰撞 判据 玻姆 时间演化 数值求解 低气压放电
• 年，卷（期）: 2011,（4）
• 页码范围: 385-391
• 页数: 7页
• 分类号: O313.4|V275
• 语种: 英文

摘要

The sheaths of a plasma containing two species of positive ion generated in a low pressure discharge （- mTorr） are studied using a fluid model. It is shown analytically that for the weakly collisional presheath, as long as the ion-ion streaming instability is absent, each ion species enters the sheath satisfying each individual Bohm criterion. The fluid equations of electrons and ions, including the time derivative terms, are solved numerically to follow the temporal evolution of the plasma and sheath. Our numerical results show that in the parameter range explored, the ion-ion streaming instability is not observed, and each ion species has its own Bohm criterion independent of the relative concentrations of the two ion species. In addition, the RF sheath is studied numerically and the similar conclusion is drawn.

作者信息

序号	姓名	单位	发文数	被引次数	H指数	G指数
1	胡业民	中国科学院合肥物质科学研究院	2	0	0.0	0.0
2	项农	中国科学院合肥物质科学研究院	3	0	0.0	0.0
3	欧靖	中国科学院合肥物质科学研究院	1	0	0.0	0.0