Showing papers by "Marshall N. Rosenbluth published in 1967"

Instabilities due to Temperature Gradients in Complex Magnetic Field Configurations

Abstract: An integral equation governing an instability due to ion temperature gradients is derived. In the presence of magnetic shear, localized non‐convective normal modes of instability are shown to exist if the relative temperature gradient is larger than that of density, unless the shear is exceedingly strong, i.e., the field shears through a large angle in the distance in which the temperature drops. Quasi‐modes which are less localized in the direction of the gradient can be constructed from these normal modes and a large thermal diffusion may be expected. Conversely the mass diffusion is shown to be rather slow so that it is reasonable to assume that an effective ``divertor'' should keep the actual heat loss quite small.

Plasma Wave Reflection in Slowly Varying Media

Abstract: Two mathematical formalisms are presented to describe wave reflection in a slowly varying spatially inhomogeneous thermal plasma described by the Vlasov equation. It is found that the transmitted wave, which is the Wentzel‐Kramer‐Brillouin solution, and the reflected wave, can be expressed in terms of the local dielectric properties of the medium. In a numerical example, it is shown that the intrinsic thermal properties of the plasma can supply reflection mechanisms that compete with the reflection coefficient predicted when the plasma is described by fluid equations.