Acoustic target characterization for inertial confinement fusion

Numerous hurdles mark the path leading to successful inertial fusion energy and these tasks are being addressed in a multinational effort. Much work at Los Alamos National Laboratory (LANL) has focused on addressing theoretical target design, target fabrication, and target characterization. Favored target designs incorporate millimeter‐size beryllium or plastic shells filled to near‐critical density with hydrogen isotopes. This fuel is then solidified at cryogenic temperatures and allowed to symmetrize through the natural process of beta layering. Implosion physics constraints demand very strict design standards on these targets in terms of layer sphericity, concentricity, and surface smoothness. Design‐size targets for the National Ignition Facility (NIF) have recently been manufactured at LANL. Resonant ultrasound spectrocopy (RUS) is now being implemented as a valuable tool in many aspects of target characterization and it is especially useful for examining the interior of opaque objects. RUS has now b...