Accession Number : ADA131173

Title :   Neutral Flow through Ion Clouds.

Descriptive Note : Technical rept.,


Personal Author(s) : Prettie,Clifford W

PDF Url : ADA131173

Report Date : 01 Dec 1982

Pagination or Media Count : 68

Abstract : Ionospheric plasma clouds exert a drag force on the neutrals flowing through them which is generally neglected in plasma evolution analyses. This drag force can be significant in barium clouds and in late time HANE plasma. The interaction between these two flows and its influence on plasma evolution and structuring are considered and presented in this report. Based on momentum considerations alone the neutral slip speed past barium ions is reduced by 1 meter per second for every 1.7 x 10 to the 15th power ions per meter squared it passes through. This significant deceleration may be considerably reduced in small or high altitude barium clouds by viscous forces; however, in many cases ion clouds produce a wake in the neutral flow. The wake of the neutral wind passing through barium clouds affects its evolution according to the cloud size, altitude, and peak ion density. The interaction between ions and neutrals may explain morphological differences between the evolution of large SPRUCE-, ESTHER- and IRIS- like clouds and small Avefria Dos-like ion clouds. The results of numerical simulations of these two different types of clouds with coupled ion-neutral flow are presented which show a tendency for the large cloud to bifurcate. The possibility that ion-neutral interaction creates neutral turbulence which in turn leads to plasma structuring is also investigated.

Descriptors :   *Nuclear explosion simulation, *Plasmas(Physics), Striations, Viscosity, High altitude, Airburst, Plasma jets

Subject Categories : Plasma Physics and Magnetohydrodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE