An NToF Suite to Measure Ion Temperature at the Z-Facility

ORAL

Abstract

Neutron time-of-flight diagnostic techniques have been employed for over 50 years of fusion experiments. In 2016 Munro[1] documented the non-thermal contributions to the neutron fusion peak spectral variance leading to the result that a single sample along a single line-of-sight is insufficient to determine T$_{\mathrm{ion}}$ in all but the most unlikely of conditions. This ambiguity is endemic to all systems of rapid fuel assemby due to incomplete conversion of directed kinetic energy into heat. Use of multiple lines-of-sight and measurements can reduce the ambiguity and uncertainty to a level sufficient to achieve a desired task. Presented is a strategy for a new nToF suite for the Z-facility at Sandia National Laboratory, in Albuqueque, NM. This new suite leverages technologies from the National Ignition Facility at Lawrence Livermore National Laboratory and deploys these in a geometric configuration that enables T$_{\mathrm{ion}}$ measurement using either D$_{\mathrm{2}}$ or DT fusing plasmas. The strategy and logic for the design, along with estimates of precision will be presented. [1] ``Impact of temperature-velocity distribution on fusion peak shape'', D. H. Munro et al. Phys. Plasmas, 24, 056301, (2017).

Authors

  • Gary Grim

    Lawrence Livermore Natl Lab

  • David Ampleford

    Sandia National Laboratories

  • Gordon Chandler

    Sandia National Laboratory, Sandia National Laboratories

  • Michael Jones

    Sandia National Laboratories

  • Kelly Hahn

    Lawrence Livermore National Laboratory, Lawrence Livermore Natl Lab, LLNL

  • Edward Hartouni

    Lawrence Livermore Natl Lab, Lawrence Livermore National Laboratory

  • Keith LeChien

    Lawrence Livermore Natl Lab

  • James Mitrani

    Lawrence Livermore National Laboratory, Lawrence Livermore Natl Lab

  • Alastair Moore

    Lawrence Livermore Natl Lab, Lawrence Livermore National Laboratory, LLNL