Particle-in-Cell Simulations of Burning ICF Capsule Implosions
Abstract
Anomalies observed in the neutron spectral shift of high-yield shots at the National Ignition Facility (NIF) suggest the presence of suprathermal ions, implying that kinetic effects play a significant role in burning inertial confinement fusion (ICF) plasmas. Furthermore, recent measurements of reaction-in-flight (RIF) neutrons offer a direct probe of the stopping power in the burning fuel region of high energy alpha particles and up-scattered fuel ions. We have developed the particle-in-cell code PICNIC, an exactly energy-conserving particle-in-cell Monte-Carlo collision (PIC-MCC) code to simulate the burn stage in ICF. We present results from 1D spherical simulations of NIF shot N210808. We find that the suprathermal ions generated by large-angle Rutherford and nuclear elastic scattering (NES) with fusion alphas produce an alpha knock-on neutron (AKN) signal consistent with experiments. We also find that the inclusion of large-angle scattering physics does not explain the anomalously large spectral shift observed in experiment.
Keywords
Cite
@article{arxiv.2506.02273,
title = {Particle-in-Cell Simulations of Burning ICF Capsule Implosions},
author = {Johannes J. van de Wetering and Justin R. Angus and W. Farmer and V. Geyko and D. Ghosh and D. Grote and C. Weber and G. Zimmerman},
journal= {arXiv preprint arXiv:2506.02273},
year = {2025}
}