Characterization of ultracold neutron production in thin solid deuterium films at the PSI Ultracold Neutron source
Year: 2023
Type: article
Abstract: We determined the ultracold neutron (UCN) production rate by superthermal conversion in the solid deuterium $({\mathrm{sD}}_{2})$ moderator of the UCN source at the Paul Scherrer Institute (PSI). In particular, we considered low amounts of less than 20 mol of ${\mathrm{D}}_{2}$, deposited on the cooled moderator vessel surfaces in thin films of a few mm in thickness. We measured the isotopic $({c}_{\text{HD}}<0.2%)$ and isomeric $({c}_{\text{para}}\ensuremath{\le}2.7%)$ purity of the deuterium to conclude that absorption and up-scattering at 5 K have a negligible effect on the UCN yield from the thin films. We compared the calculated UCN yield based on the previously measured thermal neutron flux from the heavy water thermal moderator with measurements of the UCN count rates at the beamports. We confirmed our results and thus demonstrated an absolute characterization of the UCN production and transport in the source by simulations.
Source: Physical Review C
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Awards: Precision Physics with Muons and Ultracold Neutrons II, Pushing the high intensity frontier for ultracold neutrons, Spin-spectroscopy with ultracold neutrons - Searching for dark matter and lorentz violation using spin-precessing neutrons, A novel neutronics model of the solid D2 ultracold neutron converter at PSI aiming for increasing the source intensity, Highly accurate vector gradiometers for a next-generation neutron EDM experiment, The PSI polarized ultracold neutron source: optimization and first test measurements, Improving ultracold neutron intensities for frontier precision experiments in fundamental physics, A new search for an electric dipole moment of the neutron with increased sensitivity and an improved UCN source.
OpenAlex ID: W4323355238