San Diego, California, 17-19 June 2002

Tritium Inventory of IFE Target Fabrication Facilities

A. Nobile¹, A.M. Schwendt¹, P. L. Gobby¹, W. P. Steckle¹, D. G. Colombant², J. D. Sethian², D. T. Goodin³ and G. E. Besenbruch³

1Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545

2Plasma Physics Division, Naval Research Laboratory, Washington D.C. 20375

3Fusion Group, General Atomics, San Diego, CA 92121

In this paper, the tritium inventory of direct drive Inertial Fusion Energy (IFE) target filling facilities is examined in the interest of minimizing tritium inventory. We describe a model that has been developed to evaluate tritium inventory of the target filling process as a function of filling and layering parameters, as well as target design parameters. Previous studies (Nobile, A., et al., Fusion Technology 39, 684 (2001)) showed that temperature and fill system void fraction have a significant effect on tritium inventory. The current study uses the model to examine the effect of DT ice layering time and density of the CH foam in the target on tritium inventory. The study shows that increasing the foam density and decreasing the DT-ice layering time significantly reduces the tritium inventory. Fortunately, one-dimensional target design calculations indicate that the foam density in the direct drive target can be increased to about 140 mg/cc without significant degradation of target yield. Having evaluated and minimized the theoretical tritium inventory, calculations were performed with more realistic batch filling scenarios. The inventories associated with "real" filling scenarios approaches the theoretical minimum inventory as the number of batches is increased, resulting in tritium inventories that seem acceptable for future IFE target DT filling facilities.