Fusion Science and Technology / Volume 59 / Number 1 / January 2011 / Pages 234-239
Technical Paper / Nineteenth Target Fabrication Meeting
The High Power laser Energy Research facility (HiPER) is a European project dedicated to demonstrating the feasibility of producing energy by laser-driven inertial confinement fusion. A first design of the fast ignition cryogenic target has been established. It is composed of a thin-walled microshell with an inserted gold cone and filled with deuterium-tritium (DT) fuel by means of a capillary (conically guided capsule). After assembly, targets must be tight at cryogenic temperatures (16 to 19.6 K).
In order to evaluate the manufacturing feasibility of a single-shot target prototype, a program has been adapted from the Laser Mégajoule (LMJ) cryogenic target fabrication know-how. Target component study for HiPER concerns a hollow gold cone (25-deg half-angle and [approximately]25-m thickness), a thin polymeric microshell (2-mm diameter and 3- to 10-m thickness), and a silica capillary (30-m outer diameter).
First gas-tight targets at 77 K have been produced (helium gas leak rate [approximately]1.4 × 10-11 Pam3/s). Major efforts have been focused on thin-walled microshells, robust gold cone fabrication, and target assembly (minimizing of the glue quantity as well as helium gas leak tests) and will be discussed in this paper.