  A recent neutron analysis of experiments conducted at the National Ignition
Facility (NIF) has revealed deviations from the Maxwellian distributions in the
ion relative kinetic energy of burning plasmas, with the surprising emergence
of supra-thermal deuterium and tritium (DT) ions that fall outside the
predictions of macroscopic statistical hydrodynamic models. Our
hybrid-particle-in-cell simulations, incorporating the newly-developed model of
large-angle collisions, suggest this could be attributed to the increased
significance of large-angle collisions among DT ions and \(\alpha\)-particles
in the burning plasma. Extensive investigations into the implications of
large-angle collisions in the burning plasma have yield several key findings,
including an ignition moment promotion by \(\sim 10\, {\rm ps}\), the presence
of supra-thermal ions below an energy threshold, and a hotspot expansion rate
about six times faster than expected. Furthermore, we have established the
congruency between the NIF neutron spectral moment analysis and our
simulations. Our researches on large-angle collisions in burning plasmas offer
new insights for experiment interpretation and update our understanding for new
designs of inertial confinement fusions.
