Instrumentation Workshop – Best Instruments for the Future Neutron Facility HBS

Abstract

I n recent years, various projects have worked on developing powerful accelerator-driven neutron sources based on low-energy nuclear reactions using high-current proton beams. Such High Current Accelerator-based Neutron Sources (HiCANS) aim to be the next generation neutron user facilities standing out by highly competitive instrument performance, cost-efficiency, and easy access. At the Jülich Centre for Neutron Science (JCNS) of Forschungszentrum Jülich, the project of a High Brilliance neutron Source (HBS) explores the possibilities and technical feasibility of such a novel neutron source in detail. To obtain high brilliance neutron beams, the HBS releases neutrons from tantalum targets that are irradiated by pulsed proton beams with an energy of 70 MeV, a peak current of 100 mA, and an average power of up to 100 kW. Different target stations receive pulses of different pulse lengths and repetition rates, e.g., 24 and 96 Hz, matched to the requirements of the hosted instruments. The neutron spectrum is shifted to the thermal neutron regime by moderator-reflector assemblies, which yield a brightness of 10 13 n cm −2 s −1 sr −1 Å −1 . Each target station (Figure 1) can host up to 12 instruments using individual (cold) moderators and beamlines optimized to efficiently utilize the neutrons provided. A group of instrument scientists and users from Germany and European countries were invited for a series of workshops held between June 9 and June 13, 2022, at the MLZ in Garching to discuss the suite of instruments at the target stations of the future HBS HiCANS facility and their potential performance. The workshops started with an overview of the HBS project’s current status and technical parameters. Each day addressed a specific instrument class: diffractometers, instruments for large-scale structures, spectrometers, as well as imaging and neutron analytics instruments. The first workshop presented various neutron diffractometers as e.g. a time-of-flight engineering diffractometer, a disordered materials diffractometer, a thermal powder