Cu-oleate microspheres fabricated by emulsion method as novel targets for fast ignition laser fusion experiments

We report the successful fabrication of copper (II) oleate [Cu(C18H33O2)2, Cu-oleate] microspheres as novel targets for laser fusion. Cu-oleate microspheres were prepared using emulsion method with Cu-oleate dissolved in an organic solvent. The fabricated microspheres exhibit a uniform radius of around 103 μm and a good sphericity of 0.97. The microspheres also have high atomic copper (Cu) content of ∼10 wt%, and the Cu ions are homogeneously distributed along their radii. Although defects which are 1-μm deep can be observed on the microsphere surfaces, these defects do not cause any significant perturbation that affects the resulting areal density during implosion. With good morphology, Cu content, and target performance, the Cu-oleate microspheres fabricated by emulsion method can then be used as targets for fast ignition laser fusion experiments such as FIREX. The use of these targets enables the x-ray observation of the laser-induced fast electron energy transfer on the compressed core.