High-current stream of energetic α particles from laser-driven proton-boron fusion

The nuclear reaction known as proton-boron fusion has been triggered by a subnanosecond laser system focused onto a thick boron nitride target at modest laser intensity (similar to 10(16) W/cm(2)), resulting in a record yield of generated alpha particles. The estimated value of alpha particles emitted per laser pulse is around 10(11), thus orders of magnitude higher than any other experimental result previously reported. The accelerated alpha-particle stream shows unique features in terms of kinetic energy (up to 10 MeV), pulse duration (similar to 10 ns), and peak current (similar to 2 A) at 1 m from the source, promising potential applications of such neutronless nuclear fusion reactions. We have used a beam-driven fusion scheme to explain the total number of alpha particles generated in the nuclear reaction. In this model, protons accelerated inside the plasma, moving forward into the bulk of the target, can interact with B-11 atoms, thus efficiently triggering fusion reactions. An overview of literature results obtained with different laser parameters, experimental setups, and target compositions is reported and discussed.