Beam filamentation instability drives deuterium-tritium fusion with polarized neutron emission
Year: 2026
Type: preprint
Abstract: Filamentation instabilities are generally regarded as detrimental to fast-electron transport in fusion plasmas because they increase beam divergence and redistribute deposited energy. Here, we use two-dimensional particle-in-cell simulations coupled to a spin-dependent deuterium-tritium fusion module to investigate whether filamentation can instead transfer energy from counterstreaming electrons to prepolarized fusion ions. The simulations show that magnetic filaments, together with longitudinal inductive and transverse charge-separation electric fields, accelerate initially stationary deuterons and tritons to energies at which fusion reactions occur. Over the parameter range examined, the calculated neutron yield increases with the saturated magnetic-field energy. The model further predicts anisotropic, spin-resolved neutron emission. The direction of maximum neutron polarization is approximately perpendicular to the dominant deuterium-tritium collision direction and evolves with the angular distribution of the reacting ions. These results suggest that beam filamentation can couple relativistic-electron energy to fusion ions and that polarized neutron emission may provide a reaction-weighted signature of the underlying plasma dynamics.
Source: arXiv (Cornell University)
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Awards: The Plasma-CCP Network, G117723289, G1265315240, G3103492039, G3210679044, G3880619242, G504597400, G5451727491, Multi-scale simulation of intense laser plasma interactions, G5787903551, Multi-scale simulation of intense laser plasma interactions, G6118679113, G7312410458, G7466784921, G8043434492, G8134983455, G8351509261, G9000370377
OpenAlex ID: W7221103096