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With the construction of the ESS, the European neutron user community is eagerly awaiting the commissioning of the brightest neutron source worldwide in 2021. Parallel to this, there is however the ongoing development of neutron science being undertaken at a dwindling number of neutron facilities worldwide. The Julich Centre for Neutron Science has started a project to develop and design compact accelerator-driven high brilliance neutron sources as an efficient and cost effective alternative to the current low- and medium-flux reactor and spallation sources with the potential to offer science and industry access to neutrons. The project aims to deliver a high brilliance neutron source (HBS), consisting of a compact neutron production and moderator system which provides thermal and cold neutrons with high brilliance efficiently extracted in an optimized neutron transport system. By shaping the experiment holistically from the source to the detector, neutron experiments could be set-up for specific scientific requirements in a flexible and efficient way for the neutron user.

[8th International Meeting of the Union for Compact Accelerator-driven Neutron Sources, UCANS-8, 2019-07-08 - 2019-07-10, Paris, France] 8th International Meeting of the Union for Compact Accelerator-driven Neutron Sources, UCANS-8, Paris, France, 8 Jul 2019 - 10 Jul 2019; Les Ulis : EDP Sciences, The European physical journal / Web of Conferences Web of Conferences : proceedings proceedings 231, 03006 pp. (2020). doi:10.1051/epjconf/202023103006, Published by EDP Sciences, Les Ulis

The High-Brilliance Neutron Source (HBS) project aims to design a scalable compact accelerator driven neutron source (CANS) which is competitive and cost-efficient. The concept allows one to optimize the whole facility including accelerator, target, moderators and neutron optics to the demands of individual neutron instruments. Particle type, energy, timing, and pulse structure of the accelerator are fully defined by the requirements of a given neutron instrument. In the following, we present the current status of the HBS project., Proceedings of the 14th Int. Conf. on Heavy Ion Accelerator Technology, HIAT2018, Lanzhou, China

The neutron yield of a compact accelerator driven neutron source depends strongly on the target performance. This performance is influenced by the target composition and geometry, the cooling system design and which primary particles are used. We show that the temperature difference inside the target depends directly on the target thickness determined by the ion stopping range and therefore on the type and energy of the primary particle. Deuterons with a larger stopping power show a smaller temperature difference inside the target than protons allowing thus for a better target cooling.

Organic aromatic cold neutron moderators - like mesitylene ( C 9 H 12 ) - are often much more convenient to handle and to commission than cryogenic methane or ortho/para hydrogen moderators. Although this benefit comes at the cost of reduced brilliance, mesitylene moderators are suited to enable cold neutron applications at sources where a complex traditional cold moderator system is not feasible. Developing the Julich High Brilliance neutron Source (HBS) project, we have investigated the use of such a low-dimensional mesitylene moderator with MCNP and ANSYS simulations and validated the simulations with experiments at TU Dresden's AKR-2 reactor. Here we will document the feasibility, advantages and drawbacks of such a system and give an outlook on future optimization potentials.

International Conference on Neutron Optics, NOP2017, Nara, Japan, 5 Jul 2017 - 8 Jul 2017; JPS conference proceedings 22, 011025 (2018). doi:10.7566/JPSCP.22.011025 special issue: "Proceedings of the International Conference on Neutron Optics (NOP2017)", Published by The Physical Society of Japan, Tokyo