OpenAccess

The planned upgrade of the neutron guide system at the Budapest Research Reactor (BRR) provides an opportunity to enhance the performance of its cold neutron source. In this work, two replacement concepts for the existing liquid hydrogen disk moderator are investigated: (i) a box-shaped para-hydrogen (pH2) moderator and (ii) assemblies of low-dimensional (flat) pH2 moderators. [...]

Fractal structures are often observed in small-angle scattering experiments where a simple power law q^{-\alpha} describes the scattering intensity over many orders of magnitude. Most theories, however, level off towards lower q in a Guinier scattering that describes a simple maximum size with no specific structure. [...]