PPPL-4763

Absence of Debye Sheaths Due to Secondary Electron Emission

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

Abstract:
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.
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Submitted to: Physical Review Letters, American Physical Society (May 2012)

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Download PPPL-4763 (pdf KB pp)
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