Trapped electron instability in tokamaks: analytic solutions of the two-dimensional eigenvalue problem

Technical Report · Sat Oct 01 04:00:00 EDT 1977

DOI:https://doi.org/10.2172/5367024· OSTI ID:5367024

Tsang, K. T.; Catto, P. J.

The two-dimensional eigenvalue equation for the trapped electron instability in tokamaks is solved analytically by both a perturbation technique and a more exact method of matched asymptotic expansions. The important physical effect is shown to be the spatial localization of the trapped electron term caused by the difference between the pitch of the magnetic field and that of the mode. This localization results in a completely new form for the dispersion relation and does not impede magnetic shear stabilization. Coupling of neighboring rational surfaces is shown to result in an increase of only ..pi../2 (at most) in the growth rate.

• Research Organization: Oak Ridge National Lab., Tenn. (USA)
• Sponsoring Organization: USDOE
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5367024
• Report Number(s): ORNL/TM-5970
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700107* -- Fusion Energy-- Plasma Research-- Instabilities
ANALYTICAL SOLUTION
ASYMPTOTIC SOLUTIONS
CLOSED PLASMA DEVICES
DISPERSION RELATIONS
EIGENVALUES
ELECTRONS
ELEMENTARY PARTICLES
FERMIONS
INSTABILITY
LEPTONS
PERTURBATION THEORY
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
THERMONUCLEAR DEVICES
TOKAMAK DEVICES
TRAPPED ELECTRONS
TRAPPED-PARTICLE INSTABILITY
TWO-DIMENSIONAL CALCULATIONS