A note on the Bohm-Chodura plasma sheath criterionFunded under: FP3-FUSION 11C
The ion flow velocity entering the Debye sheath must satisfy the Bohm criterion: velocity greater than or equal to sonic. The ion flow velocity entering the magnetic pre-sheath (upstream of the Debye sheath) must satisfy the Chodura criterion: velocity parallel to vector B greater than or equal to sonic. The magnetic pre-sheath is a region of quasi-neutrality, which might appear to prohibit supersonic flow. This apparent contradiction is resolved by analysing the magnetic pre-sheath region to bring out more explicitly the role played by inertia in the ExB direction, thus confirming that such supersonic flow is permitted.
Bibliographic Reference: Report: JET-P(94)52 EN (1994) 10 pp.
Availability: Available from the Publications Officer, JET Joint Undertaking, Abingdon, Oxon. OX14 3EA (GB)
Record Number: 199510082 / Last updated on: 1995-01-10
Original language: en
Available languages: en