Session FM2 - Mini-conference on ICF and HEDP Target Fabrication: Current Developments.
ORAL session, Tuesday afternoon, November 16
Room 105/106, SCC
Several new targets have recently been developed and fielded to investigate physical phenomena occurring in the high energy density regime. Phenomena studied included interacting hydrodynamic jets, hydrodynamic instabilities in convergent geometry, radiation flow, shock propagation in ignition-relevant materials, and issues associated with double shell targets for achieving ignition on NIF. Targets to study interacting hydrodynamic jets have been fabricated for a NIF campaign. Challenges associated with these targets included producing thin (150 ƒÝm) Al disks with 100 and 160 ƒÝm precisely placed high quality holes, and fabrication of a thin wall (40 ƒÝm) ¡Ñ 800 ƒÝm diameter cylindrical shock tube filled with low density (90 mg/cm3) carbonized resorcinol formaldehyde foam. Cylindrical targets to investigate hydrodynamic instabilities in convergent geometry as a function of initial surface perturbations have been fabricated. Many experimental campaigns with these targets have been conducted at OMEGA. These targets have been fabricated with a wide range of surface perturbations on an imploding Al marker layer using precision machining methods. The key challenge with these targets was fabrication of a high quality Al marker layer, and placement of specified surface features on the marker layer. Targets to investigate radiation flow and shock propagation in silicon aerogel were developed and fielded at the Sandia Z Pinch facility. The challenging feature associated with these targets was a high quality silicon aerogel disk that is attached to a gold washer containing a hole. Experiments on OMEGA have recently been conducted for the purpose of developing data on radiation absorption and shock propagation through ignition relevant materials. Specifically, we have fabricated targets for these experiments to investigate radiation absorption and shock propagation in Be-Cu alloys. The challenges associated with these targets were fabrication and characterization of very thin Be-Cu wedges, steps or flats with sinusoidal features. Experiments are being conducted to study the physics of double shell implosions in order to develop a non-cryogenic ignition target for NIF. These targets presented a number of challenges in precision machining, polymer coatings, metal coatings and precision assembly.