Recent results in the analysis of heavy-ion-beam-driven ICF targets

As a continuation of previous work on the analysis and optimization of ICF beam and target configurations, the influence of the energy deposition profile by heavy ions in the different layers of ICF capsules has been analyzed. A general conclusion obtained from the calculations is the confirmation that the hydrodynamic performance of the treated targets strongly depends on the particular ion energy deposition profile obtained along the different material zones. Moreover, the possibility of continuously locating the energy deposition front at the appropriate penetration level can avoid the undesirable fuel preheating resulting from the excessive penetration of energy deposition profiles optimized with regard to the initial target structure (before range shortening). It is worth to point out in this respect that significant reductions on the high gain (≅ 100) threshold beam energies have been estimated under assumption of the appropriate voltage tailoring for the incident ions, and that such tailoring, if technologically feasible, could be a key point for the practical obtainment of these high gains. The series of studies completed in order to optimize the structure of heavy-ion-beam-driven targets has led to the practical treatment of the critical points for the attainment of an optimized compression dynamics and to the joint definition of corresponding multilayered-target designs and energy deposition schemes. As a whole, the results obtained show heavy-ion fusion targets to be certainly promising as valid alternatives for use in ICF systems within the scope imposed by the limitations of the 1D simulation models employed, mainly related to the impossibility of consideration of asymmetry-induced effects. (orig.)