Related Experiment Video
Updated: Aug 16, 2026

How to Ignite an Atmospheric Pressure Microwave Plasma Torch without Any Additional Igniters
Published on: April 16, 2015
Excitation of toroidicity-induced Alfvén eigenmodes by the electrodes inserted in a heliotron/torsatron plasma
1Department of Energy and Engineering Science, Nagoya University, Nagoya 464-8601, Japan. matunaga@fusion.naka.jaeri.go.jp
Abstract:
A novel method of exciting shear Alfvén waves using electrodes inserted in a plasma was developed for basic study of Alfvén eigenmodes in a heliotron/torsatron plasma. The electrodes can induce excitation current along the confinement field line, and generate magnetic perturbations perpendicular to the confinement field. By sweeping the frequency of the current in a cold plasma, the toroidicity-induced Alfvén eigenmode was resonantly excited at the predicted frequency and radial location. Plasma response to the applied magnetic perturbations indicates a fairly large damping rate caused by continuum damping.
Related Concept Videos
Torque On A Current Loop In A Magnetic Field
Consider a rectangular current-carrying loop containing N turns of wire, placed in a uniform magnetic field. The net force on a current-carrying loop...
Toroids
When connected to a supply, the magnetic field generated in the toroid has field lines circular and concentric to its axis. Conventionally, the direction of this magnetic field is expressed using the right-hand rule. If the fingers of the right hand curl in the current direction, the thumb points in the...
Van de Graaff Generator
Van de Graaff uses both smooth and pointed surfaces, conductors, and insulators to generate large static charges and, hence, large voltages. A substantial excess charge can be deposited on the sphere because it moves...
Electric Field of Parallel Conducting Plates
Consider a cross-section of a thin, infinite conducting plate having a positive charge. For such a large thin plate, as the thickness of the plate tends to zero, the positive charges lie on the plate's two large faces. Without an external electric field, the...
Force On A Current Loop In A Magnetic Field
Magnetic Field due to Moving Charges
Consider a point charge moving with a constant velocity. Like the electric field, the magnetic field at any point is directly proportional to the magnitude of the charge and inversely proportional to the square of the distance between the source point and the field point. However, unlike the electric field, the magnetic field is always perpendicular to the plane containing the line...

