The development of high-intensity lasers has opened the field of nuclear reactions initiated by laser-accelerated particles. One possible application is the production of aneutronic fusion reactions for clean fusion energy production. We propose an innovative scheme based on the use of two targets and present the first results obtained with the ELFIE facility (at the LULI Laboratory) for the proton–boron-11 (p–11B) fusion reaction. A proton beam, accelerated by the Target Normal Sheat Acceleration mechanism using a short laser pulse (12 J, 350 fs, 1.056 µm, 1019 W cm−2), is sent onto a boron target to initiate fusion reactions. The number of reactions is measured with particle diagnostics such as CR39 track-detectors, active nuclear diagnostic, Thomson Parabola, magnetic spectrometer, and time-of-flight detectors that collect the fusion products: the α-particles. Our experiment shows promising results for this scheme. In the present paper, we discuss its principle and advantages compared with another scheme that uses a single target and heating mechanisms directly with photons to initiate the same p–11B fusion reaction.

Nuclear reactions initiated by laser-accelerated particle beams are a promising new approach to many applications, from medical radioisotopes to aneutronic energy production. We present results demonstrating the occurrence of secondary nuclear reactions, initiated by the primary nuclear reaction products, using multicomponent targets composed of either natural boron (B) or natural boron nitride (BN). The primary proton-boron reaction (p + 11B → 3 α + 8.7 MeV), is one of the most attractive aneutronic fusion reaction. We report radioactive decay signatures in targets irradiated at the Elfie laser facility by laser-accelerated particle beams which we interpret as due to secondary reactions induced by alpha (α) particles produced in the primary reactions. Use of a second nanosecond laser beam, adequately synchronized with the short laser pulse to produce a plasma target, further enhanced the reaction rates. High rates and chains of reactions are essential for most applications.