Average neutron energies from separated delayed-neutron precursors

Characterization of a neutron–beta counting system with beta-delayed neutron emitters

“…It should be noted that this level of agreement could only be 540 reached after correction of some bugs [48] in Geant4 which have been incorporated in version 10.0 and later versions of the code. The ratio between the counts of the inner and the outer ring of 3 He tubes is quite sensitive to the neutron energy distribution [10]. The measured ratio is 1.499(3) in quite good 545 agreement with the result of the simulation 1.52.…”

“…The process becomes dominant far enough from stability. The β-delayed neutron emission probability P n conveys information about the distribution and nature of nuclear levels populated in the decay, which is dictated by nuclear shell structure 10 and residual interactions [1]. P n values are also important inputs for the description of the astrophysical r process responsible for the synthesis of about half of the observed abundance of elements heavier than iron [2].…”

“…Tain) proven technology [7,8,9,10,11,12] of combining an array of 3 He proportional tubes, selectively sensitive to low energy neutrons, with a hydrogenous neutron energy moderator. Detectors with large solid angle and detection efficiency can be built in 25 this way.…”

“…When this is not the case the magnitude of the systematic error due to the unknown neutron energy distribution can be obtained from assumptions or 565 calculations of the β intensity distribution. For detectors having more than two rings of tubes, an improved estimate of the average neutron efficiency can be obtained using the information from the ratio of counts between different rings [10]. Table 3: Energy window for neutron emission Q βn , average neutron energy E n and Geant4 simulated average neutron detection efficiencyε n for each measured fission product and the 252 Cf calibration neutron source.…”

Delayed neutron emission probabilities of gallium, bromine, rubidium, indium, antimony, iodine, and cesium precursors

“…1, 2. Other methods to determine the sample strength involve the counting of the number of ions reaching the collector [3] or the counting of the number of atoms of a more long-lived decay product [4]. Indirect determinations of the sample strength via fission yields have often been used (cf.…”