A code package called UNÌC is currently under development at Argonne (Argonne National Laboratory). This new code package is focused on high fidelity solutions for nuclear reactor plant operations. The focus of this paper is the development of a spherical harmonics method used to solve the neutron transport equation. This new code, called PNFE, is just one of the components of UNÌC. PNFE is tar...

In the present work, the general purpose radiation transport MCNPX code (version 2.5.0) was used to evaluate the neutron fluence response matrix of the passive Bonner sphere spectrometer recently developed in our laboratory. The calculations were performed for an extended neutron incidence energy range (from 10−9 MeV to 1 GeV). Afterward, a sensitivity analysis of the main parameters affecting ...

The inner layers of a neutron star crust, composed of a Coulomb lattice of neutron rich nuclear clusters immersed in a sea of “free” superfluid neutrons, are closely analogous to periodic condensed matter systems such as electronic, photonic or phononic crystals. Applying methods from solid state physics to the neutron star context, we study the transport properties of those “free” neutrons for...

The performance of a explosives detection system based on the pulsed fast/thermal neutron analysis technique was assessed using Monte Carlo simulations. The aim was to develop and implement simulation methods, to support and advance the data analysis techniques of the characteristic -ray spectra, potentially leading to elemental characterization of innocuous objects using the full spectrum anal...

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...

Within a transport model it is shown that the neutron/proton ratio of squeezed-out nucleons perpendicular to the reaction plane, especially at high transverse momenta, in heavy-ion reactions induced by high energy neutron-rich nuclei can be a useful tool for studying the high density behavior of the nuclear symmetry energy.

The cooling theory of isolated neutron stars is reviewed. The main cooling regulators are discussed, first of all, operation of direct Urca process (or similar processes in exotic phases of dense matter) and superfluidity in stellar interiors. The prospects to constrain gross parameters of supranuclear matter in neutron star interiors by confronting cooling theory with observations of isolated ...

Within a transport model it is shown that the neutron/proton ratio of squeezed-out nucleons perpendicular to the reaction plane, especially at high transverse momenta, in heavy-ion reactions induced by high energy neutron-rich nuclei can be a useful tool for studying the high density behavior of the nuclear symmetry energy.

Nuclear logging is one of most important logging services provided by many oil service companies. The main parameters of interest are formation porosity, bulk density, and natural radiation. Other services are also provided from using complex nuclear logging tools, such as formation lithology/mineralogy, etc. Some parameters can be measured by using neutron logging tools and some can only be me...

background : in spite of clinically useful photon and electron beams, high energy linacs produce secondary particles such as neutrons (photo-neutron production). neutrons have important roles during treatment with high energy photons in terms of protection and dose escalation. in this project, neutron dose equivalent of 18 mv varian accelerators is calculated by tld600 and tld700. materials and...