Plasma confinement by surface magnetic field

The mechanism of the plasma confinement by the surface magnetic field (SURMAC) is studied in a linear device. It is confirmed that the potential distribution produced by the charge separation is essential for the plasma confinement. The invasion distance of the plasma into the magnetic wall is much shorter than the local ion gyroradius. The end loss can be reduced by bending the SURMAC coil to have a small aperture at the both ends. The density decay is approximately explained by the ambipolar diffusion across the magnetic field and the end loss. (author)