Hollow hydrogen spheres for laser-fusion targets

Many laser fusion experiments require the use of hollow spherical shells of hydrogen (deuterium-tritium mixture) as targets. We have produced hollow particles of normal hydrogen in preparation for producing shells of the various hydrogen isotopes and controlled mixtures of these isotopes. The hollow spheres were produced by ultrasonically nucleating bubbles in superheated liquid drops of hydrogen. Evaporation into the bubble increased its size and produced the shells