Indexed on: 24 Apr '08Published on: 24 Apr '08Published in: Il Nuovo Cimento B (1971-1996)
The dynamic stability of a semi-infinite composite hydromagnetic plasma has been investigated to include simultaneously the effects of Hall currents and the frictional effects with neutrals. The prevailing magnetic field is assumed to be uniform and horizontal. First it is shown that the solution is characterized by a variational principle. The explicit solution has then been obtained for a plasma of variable density. The stratification in density has been taken to be one-dimensional and in the direction of gravity. It is found that both the Hall currents and the frictional effects with neutrals have a destabilizing influence as part of the wave number range, which is stable in their absence, is rendered unstable by their presence.