Mark Chadwick

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– New accelerator-driven technologies that utilize spallation neutrons, such as the production of tritium and the transmutation of radioactive waste, require accurate nuclear data to model the performance of the target/blanket assembly and to predict neutron production, activation, heating, shielding requirements, and material damage. To meet these needs,(More)
We present an approach to uncertainty quantification for nuclear applications , which combines the covariance evaluation of differential cross-sections data and the error propagation from matching a criticality experiment using a neutron-transport calculation. We have studied the reduction in uncertainty of 239 Pu fission cross sections by using a(More)
Covariance matrix evaluations in the fast energy range were performed for a large number of actinides, either using low-fidelity techniques or more sophisticated methods that rely on both experimental data as well as model calculations. The latter covariance evaluations included in the ENDF/B-VII.1 library are discussed for each actinide separately.
This paper includes the main topics associated with seismic noise modeling. First part will describe the seismic noise modeling bases and its corresponding mathematical approaches. The second part will review the main approaches taken in practice to find the noise models. Two main research performed by Peterson [I] and McNamara [2] will be studied. The(More)
Researchers at Los Alamos National Laboratory are considering the possibility of using the Low Energy Demonstration Accelerator, constructed at Los Alamos Neutron Science Center for the Accelerator Production of Tritium Project, as a neutron source. Evaluated nuclear data are needed for the p+ 7 Li reaction, to predict neutron production from thin and thick(More)
Nucleon total reaction and neutron total cross sections to 300 MeV for 12C and 208Pb, and for 65 MeV scattering spanning the mass range, are predicted using coordinate space optical potentials formed by full folding of effective nucleon-nucleon interactions with realistic nuclear ground state densities. Good to excellent agreement is found with existing(More)
The preequilibrium (nucleon-in, nucleon-out) angular distributions of 27 Al, 58 Ni and 90 Zr have been analyzed in the energy region from 90 to 200 MeV in terms of the Quantum Moleculear Dynamics (QMD) theory. First, we show that the present approach can reproduce the measured (p,xp') and (p,xn) angular distributions leading to continuous final states(More)
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