Absence of Debye Sheaths Due to Secondary Electron Emission

M.D. Campanell, A. Khrabrov and I. D. Kaganovich

关键词: Numerical Simulation;    Sheath Shielding;    Beams;    Electron;   

DOI  :  10.2172/1062662
RP-ID  :  PPPL-4763
PID  :  OSTI ID: 1062662

学科分类：原子、分子光学和等离子物理

美国|英语

来源: SciTech Connect

【 摘 要 】

A bounded plasma where the hot electrons impacting the walls produce more than one secondary on average is studied via particle-in-cell simulation. It is found that no classical Debye sheath or space-charge limited sheath exists. Ions are not drawn to the walls and electrons are not repelled. Hence the unconfined plasma electrons travel unobstructed to the walls, causing extreme particle and energy fluxes. Each wall has a positive charge, forming a small potential barrier or "inverse sheath" that pulls some secondaries back to the wall to maintain the zero current condition.