Particle-Loss Reduction of Laser-Produced Anisotropic Plasmas by Means of a Uniform-Multipole Cusp Composite Magnetic Field Configuration

Abstract

In connection with the problems of filling a relatively large magnetic container with a clean laser-produced hot plasma, a plasma blob with initial spatial anisotropy is produced within a uniform as well as a uniform-multipole cusp composite magnetic field configuration, and its behavior is observed in some detail. The results indicate that (1) there exist two separate physical mechanisms of particle escape across magnetic field, referred to as “plasmoid-type” and “drift-type,” and (2) both types of particle losses may be drastically reduced or suppressed by the (local) employment of the composite field. The results of approximate theoretical analysis on the basis of MHD-equations show good quantitative agreement with the experimental ones, and the magnetic-shear and/or spatial-gradient of magnetic field strength in the composite field are identified to be very effective for the reduction or suppression of these particle losses.