Alfven cyclotron instability and ion cyclotron emission

Technical Report · Sat Jul 01 04:00:00 EDT 1995

DOI:https://doi.org/10.2172/90237· OSTI ID:90237

Gorelenkov, N N; Cheng, C Z

Two-dimensional solutions of compressional Alfven eigenmodes (CAE) are studied in the cold plasma approximation. For finite inverse aspect ratio tokamak plasmas the two-dimensional eigenmode envelope is localized at the low magnetic field side with the radial and poloidal localization on the order of a/{radical}m and a/(fourth root of m), respectively, where m is the dominant poloidal mode number. Charged fusion product driven Alfven Cyclotron Instability (ACI) of the compressional Alfven eigenmodes provides the explanation for the ion cyclotron emission (ICE) spectrum observed in tokamak experiments. The ACI is excited by fast charged fusion products via Doppler shifted cyclotron wave-particle resonances. The ion cyclotron and electron Landau dampings and fast particle instability drive are calculated perturbatively for deuterium-deuterium (DD) and deuterium-tritium (DT) plasmas. Near the plasma edge at the low field side the velocity distribution function of charged fusion products is localized in both pitch angle and velocity. The poloidal localization of the eigenmode enhances the ACI growth rates by a factor of {radical}m in comparison with the previous results without poloidal envelope. The thermal ion cyclotron damping determines that only modes with eigenfrequencies at multiples of the edge cyclotron frequency of the background ions can be easily excited and form an ICE spectrum similar to the experimental observations. Theoretical understanding is given for the results of TFTR DD and DT experiments with {upsilon}{sub {alpha}0}/{upsilon}{sub A} < 1 and JET experiments with {upsilon}{sub {alpha}0}/{upsilon}{sub A} > 1.

• Research Organization: Princeton Univ., NJ (United States). Plasma Physics Lab.
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC02-76CH03073
• OSTI ID: 90237
• Report Number(s): PPPL--3114; ON: DE95016239
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ALFVEN WAVES
ALPHA PARTICLES
CYCLOTRON INSTABILITY
CYCLOTRON RADIATION
CYCLOTRON RESONANCE
EMISSION SPECTRA
FUSION YIELD
INSTABILITY GROWTH RATES
JET TOKAMAK
MAGNETOACOUSTIC WAVES
PERTURBATION THEORY
PLASMA DIAGNOSTICS
PLASMA SIMULATION
TFTR TOKAMAK
THEORETICAL DATA
THERMONUCLEAR FUELS
TWO-DIMENSIONAL CALCULATIONS
WAVE PROPAGATION