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Mancusi, D.

Publications and source records attributed to Mancusi, D..

5 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Comparison of MAVRIC/MONACO and TRIPOLI-4{sup R} simulations of the LLNL pulsed spheres benchmark experiments - 25403

Simulations of the Lawrence Livermore Pulsed Spheres with MAVRIC/Monaco and TRIPOLI-4{sup R} are presented. Both codes use ENDF/B-VII.1 cross section data, but TRIPOLI-4{sup R} also uses cross section data based on JEFF-3.1.1. The MAVRIC/Monaco simulations were performed with the SCALE 6.2.2 release while the TRIPOLI-4{sup R} simulations used an internal development version of the code. For the most part, the simulated and measured neutron counts agree within 30%. Simulated gamma flux data is compared, as well. There are no measured gamma data. The agreement between the simulated gamma flux spectra is often within 10% or less, but there some notable differences, especially when comparing simulations using ENDF/B-VII.1 and JEFF 3.1.1 based cross section data. The comparison of photon simulations suggests that improvements are needed in the cross-section data, cross section processing codes, and/or transport codes and gamma measurement data is needed for experimental validation. (authors)

61 RADIATION PROTECTION AND DOSIMETRY↗
DOE OSTI2018

Determination of the Transition Temperature of a Weak Ferromagnetic Thin Film by Means of an Evolution of the Method Based on the Arrott Plots

The ferromagnetic transition temperature (T{sub c}) of a weak ferromagnetic thin film Cu{sub 0.38}Ni{sub 0.62} has been estimated by using an evolution of the Belov, Goriaga, and Arrott (BGA) model. In fact, the typically used measurements of the zero-field-cooled-field-cooled magnetic moment (m) as a function of temperature (T), the magnetic hysteresis loops (m(H)) as a function of field, and the temperature dependence of the remanent magnetic moment, performed on our sample, did not allow us to individuate precisely the value of T{sub c}, mainly due to the influence of thermal effects and noise on the weak ferromagnetic response of the sample, resulting in a large uncertainty in the estimation of T{sub c}. On the other hand, also the commonly used method of determining the T{sub c} by means of a linear extrapolation of the high-field region of m{sup 2} as a function of the normalized magnetic field (H/m) at different temperatures (Arrott curves), working though for our analyzed material, could not completely fulfill the basic assumptions of the BGA model in general. For these reasons, we have considered the analysis of the derivatives of the Arrott curves, starting from observing that the T{sub c} of the sample corresponds to the temperature where the curvature of the Arrott curves at low fields inverts. In this way, the sensitivity in the determination of the Curie point from the inductive measurements of the magnetic moment is improved while the correct assumptions of the Arrott model are also fully respected.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2017

Results of TRIPOLI-4 version 10 on the TRIPOLI-4 criticality validation suite, thermal spectra

This paper presents the results of the latest version (version 10) of TRIPOLI-4 on its criticality validation suite, thermal spectra part. The criticality validation suite is made of 148 selected ICSBEP benchmarks with various enrichments, fissile materials and spectra. The ICSBEP benchmarks computational models are prepared by the TRIPOLI-4 team and are run in the same conditions for each benchmark: initial source, number of neutrons per cycle, number of inactive and active cycles, k{sub eff} estimator and nuclear data. Comparisons are made with experimental k{sub eff}. On one case (PST-009), we have noted a discrepancy between the computational results and the experiments. This discrepancy is also found with other codes, which might indicate a possible issue with the benchmark. For all the other considered cases, uranium and plutonium solutions and fuel-rods-arrays, the agreement with the experiments is very good.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2016

Recent developments in Geant4

Geant4 is a software toolkit for the simulation of the passage of particles through matter. It is used by a large number of experiments and projects in a variety of application domains, including high energy physics, astrophysics and space science, medical physics and radiation protection. Over the past several years, major changes have been made to the toolkit in order to accommodate the needs of these user communities, and to efficiently exploit the growth of computing power made available by advances in technology. The adaptation of Geant4 to multithreading, advances in physics, detector modeling and visualization, extensions to the toolkit, including biasing and reverse Monte Carlo, and tools for physics and release validation are discussed here.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗