First wall protection schemes for inertial confinement fusion reactors

Abstract

The successful containment of thermonuclear yields ranging from 100–4000 MJ has presented a great challenge to the fusion reactor designer. It is shown that the thermal pulses associated with such pellet design can exceed the melting temperature in first walls unless either the chamber size is made unreasonably large (> 10 to 20 meters in diameter) or something is done to modify the energy spectra of the pellet debris. The various approaches to absorbing the photons and slowing down the charged particles and neutrons are reviewed. Fluidized walls and low pressure gases show great promise for protection of the cavity surfaces, but there are a number of critical experiments that need to be performed on both of these concepts before a final decision on their use in reactors can be made.