Charge screening in inertial-confinement-fusion plasmas as a possible source of non-thermal ion distributions

The plasma conditions inside a hotspot in a typical inertial confinement fusion capsule are characterized by hot temperatures and high densities relevant for both energy applications and nuclear astrophysics studies. Diagnostic tools are an essential component to understand experimental results. The neutron time-of-flight data probe the energy distribution of the neutrons produced by fusion reactions such as deuterium-tritium (DT) and deuterium-deuterium (DD). A discrepancy was recently observed between the mean and width of the energy distribution of unscattered neutrons with respect to the expectation assuming thermal DT reactions as source (known as the “isotropic-velocity anomaly”) [1].

This talk will explore possible interpretations of the anomaly in terms of charge (anti-)screening effects, which alter the nuclear fusion cross section and thus the energy distribution of reaction products. I will mention both traditional neutral-plasma screening, and more exotic plasma conditions such as a globally charged environment [2].

[1] E. P. Hartouni et al. Nat. Phys. 19, 72 (2023). DOI: 10.1038/s41567-022-01809-3

[2] S. S. Perrotta and A. Bonasera, Nuc. Phys. A 989, 168 (2019). DOI: 10.1016/j.nuclphysa.2019.06.008