Advances in Target Design for Heavy-Ion Fusion

Conference · Tue Jun 21 04:00:00 EDT 2005

DOI:https://doi.org/10.1088/0741-3335/47/12B/S27· OSTI ID:919227

Callahan, D A; Tabak, M; Bennett, G R; Cuneo, M E; Vesey, R A; Nikroo, A; Czechowicz, D; Steinman, D

Over the past few years, the emphasis in heavy ion target design has moved from the distributed radiator target to the 'hybrid' target because the hybrid target allows a larger beam focal spot than the distributed radiator ({approx} 5 mm radius rather than {approx} 2 mm radius). The larger spot relaxes some of the requirements on the driver, but introduces some new target physics issues. Most notable is the use of shine shields and shims in the hohlraum to achieve symmetry rather than achieving symmetry by beam placement. The shim is a thin layer of material placed on or near the capsule surface to block a small amount of excess radiation. While we have been developing this technique for the heavy ion hybrid target, the technique can be used in any indirect drive target. We have begun testing the concept of a shim to improve symmetry using a double-ended z-pinch hohlraum on the Sandia Z-machine. Experiments using shimmed thin wall capsules have shown that we can reverse the sign of a P{sub 2} asymmetry and significantly reduce the size of a P{sub 4} asymmetry. These initial experiments demonstrate the concept of a shim as another method for controlling early time asymmetries in ICF capsules.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA
• Sponsoring Organization: USDOE
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 919227
• Report Number(s): UCRL-CONF-213139
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ASYMMETRY
DESIGN
HEAVY IONS
PHYSICS
PLASMA
RADIATORS
SHIELDS
SYMMETRY
TARGETS
TESTING