• A novel method produces a neutron beam with Maxwellian energy distribution at kT=22 keV using a 3.4 MeV proton beam on a LiF target.
• The neutron beam has a narrow angular spread (65.0°±2.6°), enabling direct measurement of neutron capture cross-sections for s-process nuclides.
• This technique overcomes limitations of previous methods that suffered from broad angular distributions, improving accuracy in stellar nucleosynthesis studies.
• The method was validated at the China Institute of Atomic Energy, demonstrating agreement with Maxwellian distribution within experimental uncertainties.