Welter weight ion transport for diode generated ion beam inertial confinement fusion

Abstract

Summary form only given. The choice of ion species for ion beam inertial confinement fusion is driven by target design, ion beam transport and beam generation. An important question is whether heavy and light ion technologies and be extended into the welter weight regime of intermediate atomic weight. The target defines the total energy in the ion beams, the number of beams, and the temporal shape of the beams. Of the several possible methods of ion beam transport, self-pinched propagation is potentially the most attractive. This mode requires that the beam current is only partially neutralized by a background gas and uses the net current to generate a confining azimuthal magnetic field. The net current required is determined by the diode design. A formalism for comparing the beam generation and propagation has been constructed from known relations. Beam ions from Li to Cs are compared within this formalism. As the beam ion atomic number and energy increase, the anode surfaces in the diodes become smaller and the required neutralization fraction decreases. Higher than some atomic mass, the combined use of magnetically insulated diodes and self-pinched transport is no longer a useful concept and ion beam generation with a linear accelerator might be more attractive.