Ion-beam-driven lower-hybrid instability and resultant anomalous beam slowing
A lower-hybrid instability with ion cyclotron harmonics is observed to be driven by an ion beam injected obliquely to the magnetic field confining the isothermal plasma of the Q-1 double plasma device. The instability occurs with the injection of a low density, low velocity beam and propagates normal to the field with phase velocity ..omega../k/sub perpendicular/ approximately equal to u/sub b//sub perpendicular/, the perpendicular velocity component of the spiraling ions. The frequency spectrum, propagation, and growth rate are all in good agreement with a numerical calculation based on linear kinetic theory. Pulsed beams are used to follow the instability from the linearly growing stage to nonlinear saturation. The anomalous perpendicular momentum loss of the beam is examined by both direct energy analysis and by measurements of the resultant beam orbit modifications. By varying the beam parameters, a transition of the nonlinear saturation mechanism from the quasilinear to the trapping regime is demonstrated.
- Research Organization:
- Princeton Univ., N.J. (USA). Plasma Physics Lab.
- DOE Contract Number:
- EY-76-C-02-3073
- OSTI ID:
- 5160518
- Report Number(s):
- PPPL-1412
- Country of Publication:
- United States
- Language:
- English
Similar Records
Lower hydrid instability driven by a spiraling ion beam
Anomalous slowing of a perpendicularly-injected ion beam in both quasilinear and trapping regimes
Related Subjects
700107* -- Fusion Energy-- Plasma Research-- Instabilities
BEAM INJECTION
HEATING
HIGH-FREQUENCY HEATING
HYBRID RESONANCE
ICR HEATING
INSTABILITY
INSTABILITY GROWTH RATES
ION BEAM INJECTION
ISOTHERMAL PROCESSES
OPEN PLASMA DEVICES
PLASMA HEATING
PLASMA INSTABILITY
Q DEVICES
RESONANCE
THERMONUCLEAR DEVICES