Advances in implosion physics, alternative targets design, and neutron effects on heavy ion fusion reactors

The coupling of a new radiation transport (RT) solver with an existing mult imaterial fluid dynamics code (ARWEN) using Adaptive Mesh Refinement named DAFNE, has been completed. In addition, improvements were made to ARWEN in order to work properly with the RT code, and to make it user-friendlier, in cluding new treatment of Equations of State, and graphical tools for visual ization. The evaluation of the code has been performed, comparing it with o ther existing RT codes (including the one used in DAFNE, but in the single- grid version). These comparisons consist in problems with real input parame ters (mainly opacities and geometry parameters). Important advances in Atom ic Physics, Opacity calculations and NLTE atomic physics calculations, with participation in significant experiments in this area, have been obtained, Early published calculations showed that a DT, fuel with a small tritium i nitial content (x < 3%) could work in a catalytic regime in Inertial Fusion Targets, at very high burning temperatures (much greater than 100 keV). Ot herwise, the cross-section of DT remains much higher than that of DD and no internal breeding of tritium can take place, improvements in the calculati on model allow to properly simulate the effect of inverse Compton scatterin g which tends to lower T-e and to enhance radiation losses, reducing the pl asma temperature, T-i. The neutron activation of all natural elements in Fi rst Structural Wall (FSW) component of an Inertial Fusion Energy (IFE) reac tor for waste management, and the analysis of activation of target debris i n NIF-type facilities has been completed. Using an original efficient model ing for pulse activation, the FSW behavior in inertial fusion has been stud ied. A radiological dose library coupled to the ACAB code is being generate d for assessing impact of environmental releases, and atmospheric dispersio n analysis from HIF reactors indicate the uncertainty in tritium release pa rameters. The first recognition of recombination barriers in SiC, modify th e understanding of the calculation of displacement per atom, dpa, to quanti fy the collisional damage. An important analysis has been the confirmation, using Molecular Dynamics (MD) with an astonishing agreement, of the experi mental evidence of low-temperature amorphization by damage accumulation in SiC, which could modify extensively its viability as a candidate material f or IFE (fusion in general) applications. The radiation damage pulse effect has also been assessed using MD and Kinetic Monte Carlo diffusion of defect s, showing the dose and driver frequency dependences. (C) 2001 Elsevier Sci ence B.V. All rights reserved.