Plasma equilibrium and stability in a current-carrying conductor vicinity

Our paper is connected with a cycle of works on mathematical modeling of plasma confinement processes in the magnetic traps – Galateas. A magnetic field confining plasma is created in these traps by current-carrying conductors which are immersed in the plasma volume but not in contact with the hot dense plasma. The idealized models of strictly equilibrium configurations of infinitely conductive plasma in traps possessing symmetry are based on two-dimensional boundary value problems with the scalar Grad-Shafranov equation for the magnetic flux function. Magnetic traps have a perspective in the controlled thermonuclear fusion problem if plasma configurations in them are stable. In our former publications, a question about stability of the configurations around a straight conductor was raised and particularly solved. Here these studies are continued. An area of maximal pressure and a section of its decrease near the outer boundary are included into the considered vicinity. The main result is that the instabilities observed here can be weakened if the plasma pressure slowly decreases near the trap outer boundary.