Measurements of delayed neutron parameters for U-235 and Np-237

Development of a Reference Database for Beta-Delayed Neutron Emission

“…The direct methods used for measuring the macroscopic delayed-neutron characteristics from neutroninduced fission of heavy elements are based on irradiating the investigated sample by neutrons and subsequently measuring the appropriate delayed-neutron observables: the time dependence of delayed-neutron activities or the delayed-neutron energy spectrum. Neutron sources used for this purpose are mainly the neutron flux in nuclear reactors [207][208][209][210][211][212][213][214], critical assemblies [13,215,216], or electrostatic accelerator-based nuclear reactions: Li(p,n), T(p,n), T(d,n), D(d,n) [217][218][219][220][221][222][223]. All experimental methods are based on the assumption that the delayed-neutron activity arising from the irradiation of the fissionable sample can be represented by the linear superposition of the exponential decay modes, each with its own decay constant…”

High-efficiency 3He proportional counter for the detection of delayed neutrons

“…Four of the counter segments (I,11,I11 and IV) are composed of four tubes in a row and correspond to each of the four sides of the counter. Segment V consists of the remaining tubes, each separated by four tubes of the I, 11, I11 and IV sections in a way that corresponds to the four comers of the counter (Loaiza, 1997). The output signals from the neutron detector are also fed into the input synchronizer of the Pulse Arrival-Time Recording Module (PATRM ).…”