LOW-FREQUENCY INDUCTION PLASMAS.
Abstract
The possibility of generating thermal electrodeless plasmas at frequencies below the rf range through the use of magnetic materials is investigated analytically and experimentally. Existing minimum frequency and voltage criteria for the maintenance of quasi-steady, tube-filling a-c arcs are combined with the induction law to yield design criteria for a plasma transformer that has a conventional iron core and primary, but has the secondary replaced by a torus-shaped vessel that contains a single plasma turn. The feasibility of the idea is demonstrated on a small model with an iron core of 100 sq cm cross section at a frequency of 9600 Hz, generating 220 V per turn in the unloaded state. Steady discharges have been obtained in argon at pressures up to 500 Torr, in which case the plasma current at this pressure was 100 A and the maintenance voltage was 120 V. The estimated minimum dimensions for maintaining an atmospheric pressure argon plasma at 60 Hz are 30 cm for the core radius and 4 cm for the small radius of the torus. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 27, 1970
- Accession Number
- AD0704586
Entities
People
- Hans U. Eckert
Organizations
- The Aerospace Corporation