Implosion and ignition of magnetized cylindrical targets driven by heavy-ion beams

Implosions of cylindrical targets, directly driven by heavy-ion beams irradiated along the cylinder axis, are investigated by one-dimensional magneto-hydrodynamic simulations. In order to reduce heat losses from the hot fuel, which is enclosed by a metallic tamper, an axial magnetic field is introduced in the targets prior to implosions. We find that diffusive loss of magnetic flux out of the fuel leads to an accumulation of fuel material next to the cold pusher, causing a major problem for the efficiency of magnetized implosions. Magnetized target fusion (MTF) is an important application of magnetized cylindrical implosions. Looking for an optimum reference configuration for MTF with heavy-ion beams, we find the ignition threshold of magnetized cylindrical fusion targets to be at a driver pulse energy of about 10 MJ per centimetre target length; this value is nearly independent of target size and driver power, while the fuel temperature is required to be larger than 50 eV prior to implosions. Finally, we compare our reference case of an igniting MTF target to a standard indirect-drive heavy-ion fusion target.