Magnetized implosions driven by intense ion beams Available to Purchase

Intense beams of heavy ions, envisaged for the near future at the Institute for Theoretical and Experimental Physics (Moscow) and Gesellschaft für Schwerionenforschung (Darmstadt), will be well suited for conducting implosion experiments in cylindrical geometry. In such implosions, the initial pressure generated by the direct beam heating can be enhanced by more than a factor of 10. If, in addition, an external magnetic field is introduced, the effect of magnetothermal insulation may allow to reach kilovolt temperatures and significant thermonuclear neutron yields in magnetized implosions driven by the beam heating intensities as low as $ε̇≃1 TW/g.$ It is shown how the combined effect of the electrical resistivity and thermal conductivity sets a lower limit on the product $UR$ $(R$ is the radius, and $U$ is the velocity of an imploding plasma volume) as a necessary condition for the regime of self-sustained magnetized implosion (SSMI). The optimal plasma parameters required for initiation of this regime are evaluated. In cylindrical geometry, the threshold for the SSMI regime is determined by the total driver energy deposition per unit areal density of the cylinder, $ρ−1|dEb/dz| (kJ cm2/g).$ The results of one-dimensional magnetohydrodynamic simulations indicate that the advantages of magnetized implosions begin to manifest themselves at a beam energy level of $Eb≈100$ kJ.