Year: 2026
Type: preprint
Abstract: Laser-driven proton-boron fusion offers a path for generation of $α$ particles on a compact scale. Conventional solid-target experiments, however, are fundamentally limited by target degradation and low shot-repetition capacity. Here, we demonstrate a continuous laser-driven $α$ particle source utilizing target-normal sheath acceleration from a continuously replenishable ultrathin water-leaf jet target. The proton beam interacts with a downstream boron nitride converter, driving the $^{11}\text{B}(p,α)^{8}\text{Be}$ reaction which yields three $α$ particles. The measurement was repeated across $18{,}000$ consecutive shots at a rate of $10\,\text{Hz}$. The outgoing $α$-particle yield and spectral fluence were measured and benchmarked against comprehensive particle-transport simulations. The numerical and experimental results reveal a pronounced flattening in the energy-differential $α$-particle spectrum escaping from the converter, driven by depth-dependent reaction yield and stopping power effects. The sustained stable $α$-particle production at high cumulative yields paves the way for applications in targeted particle therapy and laser-driven plasma-fusion research.
Source: arXiv (Cornell University)
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, U.S. Department of Energy, U.S. Department of State, United States - India Educational Foundation, Office of Science, National Nuclear Security Administration, Bureau of Educational and Cultural Affairs, Fusion Energy Sciences, Sandia National Laboratories, SLAC National Accelerator Laboratory
Awards: G11630931, G129537217, G2153211115, G2214935549, G2678272954, G280414146, G413247060, G4252376273, G4388078820, G4771968897, G4903105778, G5339743583, G5434220800, G6109272482, G6338696783, High-Energy Laser-Proton Acceleration from Cryogenic Hydrogen, NSF-BSF: Ultrafast Laser-Electron Heating for Tailoring the Emittance and Charge of High-Energy Proton Beams, G7304238415, G855168022, G8922552302
OpenAlex ID: W7214719177