Engineering issues of gridded inertial electrostatic confinement devices

Gridded inertial electrostatic confinement (IEC) systems have shown the successful formation of ion microchannels, with very good ion focusing properties. Nevertheless, major concerns exist about the integrity of the grid due to plasma heating and neutron irradiation. In this study, a hollow tungsten grid, actively cooled by a pressurized water circuit, is considered. The heat transfer analysis will show that, 85% transparent grids of 1.6 m radius are possible for fusion powers of 860 MWth, with typical heat fluxes of ~0.32 kW/cm². Computer simulations of such grids will show that the focusing properties are strongly dependent on the outer chamber radius, and that optimum operation is obtained for grid-to-chamber radius ratios less than 0.44