Compact ultracold neutron source concept for low-energy accelerator-driven neutron sources Yun Chang Shin, W. Michael Snow, David V. Baxter, Chen-Yu Liu, Dongok Kim, Younggeun Kim and Yannis K. Semertzidis Eur. Phys. J. Plus, 136 8 (2021) 882 Published online: 26 August 2021 DOI: 10.1140/epjp/s13360-021-01740-1