Study of fast electron generation and transport in interactions of intense laser pulse with pre-plasma produced by long laser pulse on foil targets

POSTER

Abstract

The influence of pre-plasma on fast electron generation is a critical issue for fast ignition. Multi-layered targets containing a Cu fluorescence layer were irradiated by an intense laser pulse ($ I \leq 2 \times 10^{18} $ W cm$^{-2}$) at the ILE, Japan. Various scale lengths of pre-plasma were generated using a long laser pulse. $K_\alpha$ x-rays spectroscopy and imaging were employed to characterize electron generation and transport. The Cu $K_\alpha$ x-rays were viewed from the front (laser irradiated) side through an Al ablator layer that prevented direct heating of the fluor. The presence of pre-plasma caused an x-ray yield reduction ($\leq 50\%$) and created a ring structure around an x-ray bright spot. Results compared against radiation hydrodynamics and hybrid/PIC modeling will be presented.

Authors

  • T. Yabuuchi

    UCSD, UCSD, USA, University of California, San Diego

  • J.A. King

    UCSD

  • Mingsheng Wei

    University of California, San Diego, UCSD

  • B.S. Paradkar

    UCSD

  • Sophia N. Chen

    UCSD, University of California, San Diego

  • T. Ma

    University of California San Diego, UCSD, LLNL

  • F.N. Beg

    University of California, San Diego, University of California San Diego, UC San Diego, UCSD, Department of Mechanical and Aerospace Engineering, University of California San Diego

  • R.B. Stephens

    General Atomics, GA, General Atomics, San Diego

  • M. Hatakeyama

    ILE

  • N. Nakanii

    ILE

  • H. Habara

    ILE

  • Kunioki Mima

    Institute of Laser Engineering, Osaka University, ILE, Osaka U., ILE Osaka University, ILE, Institute of Laser Engineering Osaka Univ., ILE, Osaka Univ.

  • K.A. Tanaka

    ILE