Heavy-ion beam illumination on a direct-driven pellet in heavy-ion inertial fusion

Key issues in heavy-ion beam (HIB) inertial confinement fusion (ICF) include an accelerator design for an intense HIB, an efficient HIB transport, a HIB-target interaction, a reactor design, and so on. In this paper, three-dimensional computer simulations are performed for a HIB irradiation onto a direct-driven spherical fuel pellet in HIB-ICF in order to clarify dependence of multi-HIB illumination nonuniformity on parameter values of HIB illumination. For various beam parameters and reactor chamber radii we investigate the energy deposition nonuniformity using 12, 20, 32, 60, 92, and 120-beam irradiation systems. In this study, the effects of HIB temperature, HIB illumination systems, HIB emittance, and pellet temperature on the HIB illumination nonuniformity are also evaluated. In addition, the nonuniformity growth due to a little pellet displacement from a reactor chamber center is investigated. The calculation results demonstrate that we can realize a rather low nonuniform energy deposition, for example, less than 2.0 % even for a 32-beam irradiation system.