Fission yield measurements at IGISOL

Abstract

Abstract. The fission product yields are an important characteristic of the fission process. In fundamental physics, knowledge of the yield distributions is needed to better understand the fission process. For nuclear energy applications good knowledge of neutroninduced fission-product yields is important for the safe and efficient operation of nuclear power plants. With the Ion Guide Isotope Separator On-Line (IGISOL) technique, products of nuclear reactions are stopped in a buffer gas and then extracted and separated by mass. Thanks to the high resolving power of the JYFLTRAP Penning trap, at University of Jyväskylä, fission products can be isobarically separated, making it possible to measure relative independent fission yields. In some cases it is even possible to resolve isomeric states from the ground state, permitting measurements of isomeric yield ratios. So far the reactions U(p,f) and Th(p,f) have been studied using the IGISOL-JYFLTRAP facility. Recently, a neutron converter target has been developed utilizing the Be(p,xn) reaction. We here present the IGISOL-technique for fission yield measurements and some of the results from the measurements on proton induced fission. We also present the development of the neutron converter target, the characterization of the neutron field and the first tests with neutron-induced fission.

Total absorption $γ$-ray spectroscopy of the $β$ decays of $^{96\text{gs,m}}$Y

“…This is due to the fact that we were accidentally implanting some 96gs Y in a measurement of 96m Y and not intentionally a real mixture of both β-decaying states, which in this case are almost equally produced, as shown in the mass scan of Fig. 1 and in accordance with previous proton-induced fission yield measurements at IGISOL [75].…”

Total absorption γ -ray spectroscopy of the β decays of Y96gs,m

“…This is due to the fact that we were accidentally implanting some 96gs Y in a measurement of 96m Y and not intentionally a real mixture of both β-decaying states, which in this case are almost equally produced, as shown in the mass scan of Fig. 1 and in accordance with previous proton-induced fission yield measurements at IGISOL [74].…”

Identifying Inconsistencies in Fission Product Yield Evaluations with Prompt Neutron Emission

“…We have identified possible sources of these discrepancies, such as the anomalous increase in Z (A) for the JEFF-3.1.1 252 Cf(sf) evaluation, relative to ENDF-B/VII.1 or JENDL-4.0u2, which dramatically affects the derived ν. Specific nuclides have been identified as having anomalous yields and could be remeasured in future experiments [15,43]. New experiments looking to measure A, Z, TKE, and the prompt neutron emission simultaneously [44] could also provide experimental validation of the consistency checks presented here.…”