Abschätzung der für die Ionenextraktion wichtigen Parameter der Raumladungsschicht

Abstract

Abstract Ions extracted from a plasma often have to pass a space charge existing in front of the container wall. If collisions occur within the sheath, both, the ion composition and the extraction efficiency may heavily be influenced.The parameters of interest are the extension and the field strength of the sheath. A theory is presented by which these quantities can be calculated. The theory holds for a positive space charge, the orifice being biased negativ with respect to the plasma potential.Numerical results are given concerning a weekly ionized nitrogen plasma.