Amplitude Saturation of Drift Waves in a Q-Machine,
Abstract
The linear and nonlinear properties of the density gradient driven drift waves instability are studied in a single-ended Q-machine in which the drift waves occur at a radius far from the origin (-r/n dn/dr>>1) due to the particular density gradient resulting from an aperture limiter. The drift wave is observed under both collisionless and collision-dominated conditions. Agreement is noted in many respects with the predictions of slab model calculations, but effects are observed which indicate that the nonuniform radial electric field which also occurs near the aperture radius cannot be neglected in an accurate theory. The collisionless drift wave is observed at densities from 9,000/cc to 1 x 10 to the power of 9/cc. The spectral properties, spatial distribution, and stability properties are measured and compared with the predictions of linear theory. Observations of mode-mode coupling effects between drift wave modes and between the drift wave and another low frequency instability are described. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1972
- Accession Number
- AD0747852
Entities
People
- David Martin Kraybill
Organizations
- University of Illinois Urbana–Champaign