Neutron transport analysis is used to evaluate the effects of neutron calibration source position, support structure, and water coolant on the in situ calibration of the in-vessel neutron flux monitor using the micro-fission chamber (MFC) system by applying a Monte Carlo code for neutron and photon transport (MCNP). Results indicate that changing the position of a neutron calibration source lea...

This paper describes a neutron monitor which consists of a spherical neutron moderator, 12′′ in diameter, with a thermal neutron detector which detects delayed β-radiation from silver activation. The thermal neutron detector is based on four silicon diodes at the centre of the moderator, two of which are covered by silver foils, 250 μm thick, and two by tin foils, 360 μm thick. The latter two d...

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...

We investigate dynamical coupling timescales of a neutron star’s superfluid core, taking into account the interactions of quantized neutron vortices with quantized flux lines of the proton superconductor in addition to the previously considered scattering of the charged components against the spontaneous magnetization of the neutron vortex line. We compare the cases where vortex motion is const...

An explanation for the large random velocities of pulsars is presented. Like many other models, we propose that the momentum imparted to the star is given at birth. The ultimate source of energy is provided by the intense optically thick neutrino flux that is responsible for radiating the proto-neutron star’s gravitational binding energy during the Kelvin-Helmholtz phase. The central feature of...

We show that as a Type II supernova shock breaks out of its progenitor star, it becomes collisionless and may accelerate protons to energies >10 TeV. Inelastic nuclear collisions of these protons produce an approximately 1 h long flash of TeV neutrinos and 10 GeV photons, about 10 h after the thermal (10 MeV) neutrino burst from the cooling neutron star. A Galactic supernova in a red supergiant...

The HANARO neutron irradiation facility for various applications in the boron neutron capture therapy (BNCT) field was developed, and its characteristics were investigated. In order to obtain the sufficient thermal neutron flux with a low level of contamination by fast neutrons and gamma rays, a radiation filtering method was adopted. The radiation filter was designed by using a silicon single ...

Adequate description of electro and gamma nuclear physics is of utmost importance in studies of electron beam-dumps and intense electron beam accelerators. I also is mandatory to describe neutron backgrounds and activation in linear colliders. This physics was elaborated in Geant4 over the last year, and now entered into the stage of practical application. In the Geant4 Photo-nuclear data base ...

We consider dissipative effects occurring in the optically thick inner parts of the rela-tivistic outflows producing gamma-ray bursts and X-ray flashes, emphasizing specially the Comptonization of the thermal radiation flux that is advected from the base of the outflow. Such dissipative effects –e.g. from magnetic reconnection, neutron decay or shocks – would boost the energy density of the the...