Evidence of non-Maxwellian ion velocity distributions in spherical shock-driven implosions

• Published in: Physical review. E 2023-09, Vol.108 (3), p.035201-035201, Article 035201
• Main Authors: Mannion, O. M., Taitano, W. T., Appelbe, B. D., Crilly, A. J., Forrest, C. J., Glebov, V. Yu, Knauer, J. P., McKenty, P. W., Mohamed, Z. L., Stoeckl, C., Keenan, B. D., Chittenden, J. P., Adrian, P., Frenje, J., Kabadi, N., Gatu Johnson, M., Regan, S. P.
• Format: Article
• Language: English
• Subjects: 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; Direct drive; High-energy-density plasmas; Inertial confinement fusion; Nuclear fusion
• ISSN: 2470-0045; 2470-0053
• DOI: 10.1103/PhysRevE.108.035201

The ion velocity distribution functions of thermonuclear plasmas generated by spherical laser direct drive implosions are studied using deuterium-tritium (DT) and deuterium-deuterium (DD) fusion neutron energy spectrum measurements. A hydrodynamic Maxwellian plasma model accurately describes measurements made from lower temperature (< 10 keV), hydrodynamiclike plasmas, but is insufficient to describe measurements made from higher temperature more kineticlike plasmas. The high temperature measurements are more consistent with Vlasov-Fokker-Planck (VFP) simulation results which predict the presence of a bimodal plasma ion velocity distribution near peak neutron production. Furthermore, these measurements provide direct experimental evidence of non-Maxwellian ion velocity distributions in spherical shock driven implosions and provide useful data for benchmarking kinetic VFP simulations.