Frontiers in Physics (Sep 2024)

A kinetic study of fusion burn waves in compressed deuterium–tritium and proton–boron plasmas

  • Michael J. Lavell,
  • Michael J. Lavell,
  • Ayden J. Kish,
  • Ayden J. Kish,
  • Andrew T. Sexton,
  • Andrew T. Sexton,
  • Eugene S. Evans,
  • Ibrahim Mohammad,
  • Sara Gomez-Ramirez,
  • Sara Gomez-Ramirez,
  • William Scullin,
  • Marcus Borscz,
  • Marcus Borscz,
  • Sergey Pikuz,
  • Thomas A. Mehlhorn,
  • Thomas A. Mehlhorn,
  • Max Tabak,
  • Greg Ainsworth,
  • Adam B. Sefkow,
  • Adam B. Sefkow,
  • Adam B. Sefkow,
  • Adam B. Sefkow

DOI
https://doi.org/10.3389/fphy.2024.1440037
Journal volume & issue
Vol. 12

Abstract

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We present particle-in-cell simulations with Monte Carlo collisions of fusion burn waves in compressed deuterium–tritium and proton–boron plasmas. We study the energy balance in the one-dimensional expansion of a hot-spot by simulating Coulomb collisions, fusion reactions, and bremsstrahlung emission with a Monte Carlo model and inverse bremsstrahlung absorption using a new PIC model. This allows us to self-consistently capture the alpha particle heating and radiative losses in the expanding hot-spot and surrounding cold fuel. After verifying our model in a code-to-code comparison with both kinetic and fluid codes for the case of a deuterium–tritium hot-spot, we simulate the expansion of a proton–boron hot-spot initialized at 200 keV and 1,000 g/cm3. Our model predicts that energy radiated by the hot-spot is recaptured by the surrounding high-density opaque fuel reducing the expansion work done by the propagating burn wave. As a result, we find the net fusion energy produced over the course of $20$∼ps is twice the initial hot-spot energy independent of whether radiation physics is included.

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