Determination of natural uranium fission rate in fast spallation and fission neutron field: An experimental and Monte Carlo study

Inelastic cross sections in relativistic deuterons on Lead reactions

“…The neutron spectrum contains a hard part, corresponding to nuclear cascade effects, which take place in the target. The [29,30] and also confirmed experimentally during these experiments [31]. Protons escaping the Ublanket surface derive from direct interactions of high energy neutrons and protons produced by the target and induce further reactions at the Uranium mass, during the internuclear cascade stage.…”

Fission rates of nuclides in the neutron field formed on the surface of a massive lead target irradiated with protons at energy of 5.0 Gev

“…However, on the side surface of extended targets, the contribution of such reactions in the total fission rate has been demonstrated to be negligible (Hashemi-Nezhad et al, 2008). Therefore, in the investigated neutron system, any change in the fission rate of, for instance, 232 Th along the Z and Y directions will characterize spatial distribution of fast neutrons with energy exceeding its fission threshold (about 1.4 MeV).…”

Dose measurements around spallation neutron sources

“…The polyethylene moderator reduced the neutron ambient dose equivalent measured at the U-blanket surface $60 times for 0.7 GeV and 30 times for 2 GeV. The neutron spectrum produced by the 'E þ T' set-up was calculated using MCNPX and DCM/DEM codes (26,27) . According to the Monte Carlo calculation of the neutron spectrum, in which all neutrons are taken into account (including neutrons above 3 MeV), the moderator diminishes the neutron dose $100 times for 1 GeV proton beam.…”

“…In order to calculate the neutron spectrum after the shielding material, the neutron spectrum produced by the spallation sources was taken from the calculations made using the Monte Carlo DCM/DEM code (26) . In calculations, the statistical errors ranged between 3 and 6% (27) . The neutron ambient dose equivalent was estimated by taking into account the dose equivalent factor H*(10) (23,24) for each energy point of the calculation.…”