Neutron Source from (γ,n) Reactions at a Laser-Plasma Accelerator and Its Use for Electron Beam Characterization

Compact laboratory neutron sources play a crucial role in both fundamental physical research and practical applications, such as neutron radiography and spectroscopy. One of the most promising strategies to develop such a source is the use of laser-plasma accelerators of electrons or ions and the subsequent initiation of nuclear reactions (γ, n ), ( p , n ), or ( d , n ) with the release of neutrons. In this study, we propose a neutron source based on (γ, n ) photodisintegration reactions and characterize it using an electron beam from a 1‑TW laser-plasma accelerator. The maximum neutron flux reaches ~10 5 neutrons/s srad at a laser-radiation efficiency of ~10 6 neutrons/J. While maintaining efficiency and increasing the energy of the laser pulse by a factor of 10, the neutron flux becomes sufficient for several applications. To investigate neutron production using electron beam parameters measured in experiments, we conduct numerical Monte Carlo simulations. Recording the number of neutrons generated in an experiment can be used to estimate the charge and average energy of accelerated electrons. The simulation results show good agreement with values measured by standard beam-diagnostic tools, confirming the accuracy of our approach.