as a result of being hydrogenous moderators, several landmine detection methods based onnuclear techniques have been suggested in recent years. because of elastic scattering and moderating neutrons from hydrogen atoms in landmines, detection of backscattered neutron shows an anomaly in the reflected thermal neutrons count when a detector scans over a mine. on landmine detection using neutron so...

Abstract A rank 2 dimension 3 tensor formulation for polarized neutron transport in a magnetic field is derived. Using this formulation, the rotating problem revisited to produce single × vector-transformation matrix that describes polarization transport. That result then used fashion new strategy numerical approximation of an arbitrary using time-dependent perturbation theory.

This paper presents two improvements to speed up the Monte-Carlo simulation of neutron noise experiments. The first one is to separate the actual Monte Carlo transport calculation from the digital signal processing routines, while the second is to introduce non-analogue techniques to improve the efficiency of the Monte Carlo calculation. For the latter method, adaptations to the theory of neutr...

Background: High density concrete is extensively used for efficient radiation attenuation in radiotherapy rooms and nuclear reactors. Over the past eight years, some efficient galena-based concrete samples for shielding X or gamma rays was produced. The goal of this study was to produce a novel high density concrete against neutron and photon radiations using tourmaline and galena. Materials an...

Starting from the transport equation, a systematic homogenization theory and a self-consistent dohomogenization theory for fuel assemblies have been developed using a multiple-scales asymptotic expansion method. The resulting theory provides a framework for coarsemesh nodal diffusion calculations of light water reactors. The theoretical development is carried out through second order in a small...

We have determined for the first time the velocity distribution of neutrons from a solid H2 ultracold neutron (UCN) source. The spectrum rises sharply above 4.5m/s and has a maximum around 7m/s after transport in an 8m long guide. The number of neutrons in the UCN velocity range (< 7m/s) may be increased by a factor of two by placing the experiment 1m above the UCN source level. PACS. 29.25.Dz ...

The paper addresses a system of constant support of neutron-physical computations, in particular, the energy release computation in the group transport approximation, that has been developed by RFNC-VNIIEF. The idea of the system is using a closed processing chain of data manipulation: operation with libraries of evaluated neutron data, development of recommendations on using one or another lib...

Monte Carlo methods are frequently used for neutron and radiation transport. These methods have several advantages, such as relative ease of programming and dealing with complex meshes. Disadvantages include long run times and statistical noise. Monte Carlo photon transport calculations also often suffer from inaccuracies in matter temperature due to the lack of implicitness. In this paper we d...

Introduction: In recent years, a number of studies [1,2,3] have been published using data from the Lunar Prospector Neutron Spectrometer (LP-NS) to identify and quantify anomalously high hydrogen abundances near the poles of the Moon, which may be in the form of water ice. If water ice is indeed present at the lunar poles in high enough abundance, this could provide a critical resource for futu...

Some recent neutron scattering works on CeRhIn5 and Ce2RhIn8, together with related resistivity and specific heat measurements, are summarized. In spite of its layered crystal structure, CeRhIn5 is shown to be 3 dimensional both magnetically and in transport. We also find that the Fisher-Langer behavior is closely followed in CeRhIn5. This may circumvent the Kondo lattice model and support appl...