The distribution of neutron population in nuclear reactor is described by using transport equations. One of possible approximations of neutron transport equation is given by the neutron diffusion equation. The paper presents numerical solution method of one group neutron diffusion equation with one group of delayed neutrons.

We present a neutron scattering study of the structure and diffusion of myoglobin solutions at high concentration. The protein–protein structure factor was determined by small angle neutron scattering (SANS) measurements using mean spherical analysis (MSA), and the intermediate scattering function was measured by neutron spin-scho spectroscopy. We observe the cross-over between self-diffusion a...

Neutron radiography (NR) can investigate the diffusion mechanisms of moisture transport within the silica gel material. Dynamic neutron radiography (DNR) possesses the possibility to investigate the moisture profile inside the silica gel filter. The technique explained the relationship between moisture movement and time. This study investigated the diffusion mechanisms (absorption and infiltrat...

To simulate the behaviour of a nuclear power reactor it is necessary to be able to integrate the time-dependent neutron diffusion equation inside the reactor core. In particular, we will consider here VVER-type reactors which use the neutron diffusion equation discretized on hexagonal meshes. Several algorithms to integrate the time dependent neutron diffusion equation have been developed, by m...

Volumetric adsorption and quasielastic neutron scattering are used to study the diffusion and thermodynamics of sorbed H2 in the graphite intercalation compound KC24. A sorption enthalpy of 8.5 kJ/mol at zero coverage is determined from H2 adsorption isotherms. From measurements of total elastic-neutron-scattering intensity as a function of temperature, a melting transition of the H2 adsorbate ...

The quasi-elastic neutron scattering (QENS) technique was first used to derive self-diffusivities of hydrocarbons in zeolites, but transport diffusivities of deuterated molecules and of molecules which do not contain hydrogen atoms can now be measured. The technique allows to probe diffusion over length scales ranging from an Å to hundreds of Å. The mechanism of diffusion can thus be followed f...

Neutron diffusion equation is being used to estimate the safety margin of a neutronic parameter. The assessment of safety margin requires variability and uncertainty analysis. When the variation of sensitive parameter is varying in an imprecise manner, the evaluation of safety margin is very difficult using probabilistic analysis. However, fuzzy set theory based approach may be used to estimate...

Despite its tremendous importance for the understanding of underlying mechanisms and for the input in modeling and simulation of processes alike, accurate experimental diffusion data in liquid metals and alloys are rare. Common techniques exhibit several drawbacks that in most cases prevent an accurate measurement of diffusion coefficients convective contributions during diffusion annealing are...

In this electronic article we use the one-dimensional multigroup neutron diffusion equation to reconstruct the neutron flux in a slab reactor from the nuclear parameters of the reactor, boundary and symmetry condition, initial flux and . The diffusion equation was solved analytically for one single homogeneous fuel region and for two regions considering fuel and reflector. To validate the metho...