Proof-of-principle experiment for laser-driven cold neutron source

Abstract

The scientific and technical advances continue to support novel discoveries by allowing scientists to acquire new insights into the structure and properties of matter using new tools and sources. Notably, neutrons are among the most valuable sources in providing such a capability. At the Institute of Laser Engineering, Osaka, the first steps are taken towards the development of a table-top laser-driven neutron source, capable of producing a wide range of energies with high brightness and temporal resolution. By employing a pure hydrogen moderator, maintained at cryogenic temperature, a cold neutron ($\le 25\text{meV}$) flux of $\sim 2\times {10}^3{\text{n/cm}}^2$/pulse was measured at the proximity of the moderator exit surface. The beam duration of hundreds of ns to tens of $\mathrm{\mu }\text{s}$ is evaluated for neutron energies ranging from 100s keV down to meV via Monte-Carlo techniques. Presently, with the upcoming J-EPoCH high repetition rate laser at Osaka University, a cold neutron flux in orders of $\sim 1\times {10}^9{\text{n/cm}}^2/\text{s}$ is expected to be delivered at the moderator in a compact beamline.