Journal Article

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. [...]

We investigated the lattice dynamics of quasi-two-dimensional Pd-intercalated ErTe3 in relation to its charge-density-wave (CDW) transitions by means of x-ray diffuse and meV-resolution inelastic x-ray scattering. In pristine ErTe3 , CDW order develops at orthogonal in-plane wave vectors q𝑐1=(0,0,0.29) (the 𝑐−CDW) and q𝑎2=(0.31,0,0) (the 𝑎−CDW), with transition temperatures 𝑇𝑐1=270K and 𝑇𝑎2=160K, respectively. [...]

Prompt gamma rays produced by inelastic scattering of fission neutrons on samarium and dysprosium were measured with the instrument FaNGaS (Fast Neutron-induced Gamma-ray Spectrometry) at Heinz Maier-Leibnitz Zentrum (MLZ). Relative intensities and production cross sections for 288 gamma lines (140 for samarium, 148 for dysprosium) were calculated considering interferences from radiative capture lines. [...]

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. [...]