The authors investigate the magnetic configuration of a three-turn helical magnetic field through which an axial current flows and which has three spatial magnetic axes. It is shown that, near the spatial axes, the cross-sections of the magnetic surfaces are ellipses lying in the planes perpendicular to the axes. The parameter values for which the configuration concerned possesses, near one of the spatial axes, an angle of torsion of the magnetic field lines, shear and minimum average magnetic field is considered.

In the case of high-intensity plasmons, interaction processes among the plasmons are more probable than interaction processes of plasmons with plasma particles; plasma relaxation occurs in two stages: first, statistical equilibrium in the plasmon sub-system is established, characterized by a temperature different from that of particles, and then in a slower process equality of plasmon and particle temperatures is established.The plasmon energy may be increased by slowly modulating the external magnetic field on which the plasmon frequencies depend. The energy pumped into the plasmon sub-system by this method — which may be called the method of magnetic pumping — may be much higher than the Joule heat immediately obtained by the particles. The energy obtained by plasmons will be transferred slowly to the particles; in the plasmon sub-system itself a stationary energy level will be established. Thus, in a non-isothermal plasma mainly the electrons will be heated.

The authors investigate analytically the changes which occur in a configuration with a helical magnetic axis upon bending to form a torus. Such a magnetic configuration can be created by various combinations of magnetic fields produced by helical conductors. In the calculations it is assumed that the pitch of the helical winding and the radius of the circular axis of the torus are significantly greater than the minor radius of the torus. This means that δ = b/R ≪ 1 and ε = ℓb/R ≪ 1, where b and R are, respectively, the minor and major radii of the torus and ℓ is the number of turns of the helical conductor around the torus. Toroidality is regarded as a perturbation superposed on the configuration with a helical magnetic axis. The authors consider the conditions under which the helical magnetic axis breaks down. The distance to which the resulting magnetic axes move away from the magnetic axis of the unperturbed configuration is indicated approximately.

The authors examine the magnetic configuration of a one-turn helical magnetic field in the presence of an axial current. Particular attention is paid to the properties of the rotational transform of the magnetic field lines and to the minimum of the mean magnetic field. A relationship is found between negative V“(ø) and shear, on the one hand, and the structural features of the configuration, on the other.It is shown at what parameter values the configuration in question possesses closed magnetic surfaces surrounding the helical axis, an angle of rotational transform, shear and a minimum of the mean magnetic field.

This paper is a study of plasma equilibrium in Vintotrons toroidal traps with a spatial magnetic axis established by various combinations of magnetic fields from helical conductors. The authors determine the displacement of the vacuum magnetic axis in the presence of a plasma as a function of the relationship between the curvature of the helical magnetic axis, the curvature of the torus and a parameter characterizing the ellipticity of the vacuum magnetic surfaces. The limiting equilibrium values of are determined from the displacement of the magnetic axis. Characteristic equilibrium values of β are compared for Vintotrons and stellarators. The authors also discuss the possible effects of resonance phenomenon which can occur in a toroidal Vintotron in the presence of a plasma.