Characterization of cluster/monomer ratio in pulse supersonic gas jets

ORAL

Abstract

We determine cluster mass fraction $f_c$({\boldmath $r,t$}) at position {\boldmath $r$} within, and time $t$ after firing, a pulsed supersonic gas jet by measuring femtosecond evolution of the jet's refractive index by single-shot frequency domain holography. A fs pump pulse singly ionizes monomers, while quasi-statically ionizing and heating clusters to a level at which recombination remains negligible as clusters expand. Under these conditions, index evolves in two simple steps corresponding to monomer and cluster contributions, allowing recovery of $f_c$ without detailed cluster dynamic modeling. Variations of $f_c$ with $t$ are measured.

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Authors

  • Richard Korzekwa

    Institute for Fusion Studies, University of Texas at Austin, Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712

  • Xiaohui Gao

    Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712

  • Xiaoming Wang

    Institute for Fusion Studies, University of Texas at Austin, Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712

  • Bonggu Shim

    Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712

  • Alexey Arefiev

    Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712

  • Mike Downer

    University of Texas at Austin, Dept. of Physics, UT Austin, Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712