Negative-Ion-Source Modeling: From Expansion to Extraction Region

In a negative-ion source, the vibrational kinetics of molecules H
₂
and the negative-ion H
^-
transport are both important in order to understand and optimize H
^-
extraction. In this paper, two different particle models are developed, simulating the expansion and extraction regions of a radio-frequency inductively coupled plasma negative-ion source. These models show the importance of gas- and plasma-surface interaction in the vibrational excitation of molecules and in the direct production of negative ions from the wall.