HOLLOW FOAM MICROSHELLS FOR LIQUID-LAYERED CRYOGENIC INERTIAL CONFINEMENT FUSION-TARGETS

Future U.S. inertial confinement fusion (ICF) targets will use capsule s, 1-2 mm in diameter, with uniform 100 mu m thick, cryogenic fuel lay ers. Research is currently underway to identify optimal methods for pr oducing these thick, uniform layers. One method is to use a spherical polymer foam layer within a full density polymer overcoat to support t he fuel. Targets of this type, 0.4-0.8 mm in diameter, with 10-30 mu m walls, have been developed by the Institute of Laser Engineering at O saka University, Japan. Reported here are the results obtained from wo rk to extend the method to the future ICF target design. Overcoated fo am shells of the proper dimensions were produced, but their optical pr operties precluded the use of current diagnostics to determine the amo unt and uniformity of the fuel fill. Briefly outlined are options for improving the optical properties. (C) 1995 American Vacuum Society.