General use of low-dimensional moderators in neutron sources

The European Spallation Source (ESS) will use low-dimensional moderators for cold and thermal neutron production. Low-dimensional moderators deliver higher slow neutron brightness compared to conventional volume moderators. The concepts developed at ESS could be used in reactors and compact neutron sources to reach large increases in neutron flux to the experiments, compared to common practice. For reactors, the smaller volume of the moderators allows positioning them at the optimum flux region. For compact neutron sources, the reduced heat deposition and lower radiation environment allows for particularly efficient implementation of the ESS concepts. Using tube moderators in a compact source would allow reaching a higher brightness per unit yield at least a factor of 4, with respect to a spallation source.