Harmonic launching of ion Bernstein waves via mode transformation

Journal Article · Sat Jan 01 04:00:00 EST 1983 · Phys. Fluids; (United States)

DOI:https://doi.org/10.1063/1.863972· OSTI ID:6521625

Ono, M; Wong, K L; Wurden, G A

Ion Bernstein wave excitation and propagation via finite ion-Larmor-radius mode transformation are investigated theoretically and experimentally. It is shown that in the ion cyclotron range of frequencies ..omega..< or approx. =4..cap omega../sub i/, with modest ion temperatures (T/sub i/< or approx. =10 eV), the finite-Larmor-radius effect removes the wave singularity at the lower-hybrid resonance layer, enabling an externally initiated electron plasma wave to transform continuously into an ion Bernstein wave. In an ACT-1 hydrogen plasma (T/sub e/approx. =2.5 eV, T/sub i/< or approx. =2.0 eV), externally excited ion Bernstein waves have been observed for ..omega..< or approx. =2..cap omega../sub i/ as well as for ..omega..< or approx. =3..cap omega../sub i/. The finite ion-Larmor-radius mode transformation process resulting in strong ion Bernstein wave excitation has been experimentally verified. Detailed measurements of the wave dispersion relation and of the wave-packet trajectory show excellent agreement with theory. The dependence of the excited ion Bernstein wave on the antenna phasing, on the plasma density, and on the neutral pressure (T/sub i/) is also investigated. The present work provides information relevant to the physics of ion Bernstein wave propagation and waveguide coupling as well as to the rf--plasma interaction during ion-cyclotron-range-of-frequency heating in fusion plasmas.

• Research Organization: Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543
• DOE Contract Number: AC02-76CH03073
• OSTI ID: 6521625
• Journal Information: Phys. Fluids; (United States), Journal Name: Phys. Fluids; (United States) Vol. 26:1; ISSN PFLDA
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700108* -- Fusion Energy-- Plasma Research-- Wave Phenomena
BERNSTEIN MODE
CHARGED PARTICLES
COUPLING
DISPERSION RELATIONS
ELEMENTS
ENERGY-LEVEL TRANSITIONS
EXCITATION
HEATING
HYDROGEN
IONS
LARMOR RADIUS
NONMETALS
OSCILLATION MODES
PLASMA
PLASMA DENSITY
PLASMA HEATING
PRESSURE DEPENDENCE
TORI
TRAJECTORIES
WAVE PACKETS
WAVE PROPAGATION