The HERMES reflectometer at the JULIC Neutron Platform

Abstract

HERMES is a time-of-flight reflectometer that operated at the Orphée reactor until 2019. In 2022, HERMES was installed at the JULIC (Jülich Light Ion Cyclotron) Neutron Platform as part of a collaboration between the Laboratoire Léon Brillouin and the Jülich Centre for Neutron Science. The main goal of the current setup is to probe the viability of neutron instrumentation at a High Current Compact Accelerator-driven Neutron Source (HiCANS). As the flux at the JULIC neutron platform is several orders of magnitude lower than the original Orphée flux or the expected flux for a HiCANS, our current objective is to perform reflectivity experiments with supermirrors as a proof of concept. Nevertheless, Monte-Carlo simulations showed that the HERMES instrument’s performance at a HiCANS such as HBS or ICONE could match that of reflectometry instruments operating at research reactors or spallation sources. An experiment with a supermirror carried out in December 2022 allowed us to preliminary prove the feasibility of this kind of experiments at an accelerator-driven neutron source.