Published online by Cambridge University Press: 09 March 2009
A spherical scheme is introduced for indirect drive, having as reference the application to inertial fusion energy. The concept uses the transmission of a radiation wave through a high-Z, low-density spherical radiator surrounding the capsule to be imploded. The low conversion efficiency to in-cavity radiation is somewhat compensated by using modest radiator-to-capsule gaps, the smoothing effects on the longest dominant nonuniformity wavelengths due to this separation being of the order of 10. Another factor of the order of 100–500 is related to the consequent use of a large number of beams. From the application of the loop condition relative to power plants, it is found that this approacrTbecomes practicable if drivers with efficiencies greater than 10% are assumed and if the fraction of circulating power is allowed to be 0.5, this implying a unitary cost of energy about a factor 1.5 greater than that associated to the more conventional fraction of 0.25.