Investigation of an ion-ion hybrid Alfvén wave resonator
Abstract
A theoretical and experimental investigation is made of a wave resonator based on the concept of wave reflection along the confinement magnetic field at a spatial location where the wave frequency matches the local value of the ion-ion hybrid frequency. Such a situation can be realized by shear Alfvén waves in a magnetized plasma with two ion species because this mode has zero parallel group velocity and experiences a cut-off at the ion-ion hybrid frequency. Since the ion-ion hybrid frequency is proportional to the magnetic field, it is expected that a magnetic well configuration in a two-ion plasma can result in an Alfvén wave resonator. Such a concept has been proposed in various space plasma studies and could have relevance to mirror and tokamak fusion devices. This study demonstrates such a resonator in a controlled laboratory experiment using a H+-He+ mixture. The resonator response is investigated by launching monochromatic waves and impulses from a magnetic loop antenna. The observed frequency spectra are found to agree with predictions of a theoretical model of trapped eigenmodes.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jan 01, 2013
- Source ID
- 10.1063/1.4775777
Entities
People
- G. J. Morales
- J. E. Maggs
- S. T. Vincena
- W. A. Farmer
Organizations
- Office of Naval Research
- United States Department of Energy