Generation of radicals by laser-ablation and their application to beam source

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A variety of radicals was generated directly from solid targets by laser abation. Characteristics of the radicals were investigated by laser-induced fouorescence spectroscopy, in order to access the applicability for the radical sources. The results are summarized as follows.(1) Ba, Y,YO and BaO radicals were generated from a laser-ablated YBa_2Cu_3O_<7-x> target.(2) It was found that the kinetic energy of YO molecules reached upto 10eV.On the other hand, the rotational energy distribution was measured to be arount 0.2eV.It is shown that the most of the energy of the ejected molecules was transported as a kinetic energy.(3) Atomic species were mainly ejected from laser-ablated Al_2O_3, Si_3N_4 and BaTiO_3 targets(4) It was found that velocity distribution of ejected atoms were well described by a two-components shifted Maxwellian distribution.(5) Al atomic beam was generated by slitting the Al plume produced by the ablation and temporal developments of its density distribution were visualized by imaging laser-induced fluorescence spectroscopy. It was clearly demonstrated that high-density and high-energy neutral beam can be easily produced by the present technique.(6) The effect of the cumulative ablation of the targets on the ejection of radicals were investigated. It was found that more particulates and less radicals were ejected, as the target was ablated cumulative by. An empirical fomula which described the degradation of the target was proposed.