Cavallaro, M., De Napoli, M., Cappuzzello, F., Orrigo, S. E. A., Agodi, C., Bondi, M., et al. (2017). Investigation of the Li-10 shell inversion by neutron continuum transfer reaction. Phys. Rev. Lett., 118(1), 012701–5pp.
Abstract: This Letter reports a study of the highly debated 10Li structure through the d(Li-9,p)Li-10 one-neutron transfer reaction at 100 MeV. The Li-10 energy spectrum is measured up to 4.6 MeV and angular distributions corresponding to different excitation energy regions are reported for the first time. The comparison between data and theoretical predictions, including pairing correlation effects, shows the existence of a p(1/2) resonance at 0.45 +/- 0.03 MeV excitation energy, while no evidence for a significant s-wave contribution close to the threshold energy is observed. Moreover, two high-lying structures are populated at 1.5 and 2.9 MeV. The corresponding angular distributions suggest a significant s(1/2) partial-wave contribution for the 1.5 MeV structure and a mixing of configurations at higher energy, with the d(5/2) partial-wave contributing the most to the cross section.
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Rasco, B. C., Brewer, N. T., Yokoyama, R., Grzywacz, R., Rykaczewski, K. P., Tolosa-Delgado, A., et al. (2018). The ORNL analysis technique for extracting beta-delayed multi-neutron branching ratios with BRIKEN. Nucl. Instrum. Methods Phys. Res. A, 911, 79–86.
Abstract: Many choices are available in order to evaluate large radioactive decay networks. There are many parameters that influence the calculated beta-decay delayed single and multi-neutron emission branching fractions. We describe assumptions about the decay model, background, and other parameters and their influence on beta-decay delayed multi-neutron emission analysis. An analysis technique, the ORNL BRIKEN analysis procedure, for determining beta-delayed multi-neutron branching ratios in beta-neutron precursors produced by means of heavy-ion fragmentation is presented. The technique is based on estimating the initial activities of zero, one, and two neutrons occurring in coincidence with an ion-implant and beta trigger. The technique allows one to extract beta-delayed multi-neutron decay branching ratios measured with the He-3 BRIKEN neutron counter. As an example, two analyses of the beta-neutron emitter Cu-77 based on different a priori assumptions are presented along with comparisons to literature values.
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Saha, S., Arici, T., Gerl, J., Gorska, M., Pietralla, N., Davinson, T., et al. (2020). On the 6-detection efficiency of a combined Si and plastic stack detector for DESPEC. Nucl. Instrum. Methods Phys. Res. A, 975, 164196–8pp.
Abstract: A Geant4 simulation has been carried out in order to determine the beta-detection efficiency of a rare isotope beam implantation setup, for decay spectroscopy experiments, comprising a number of Double Sided Silicon Strip Detectors (DSSSDs) and two plastic scintillation detectors placed upstream and downstream. The absolute efficiency for the emitted beta-particle detection from radioactive fragments implanted in the DSSSDs using fast-timing plastic-scintillator detector, is calculated. The detection efficiency of the setup has been studied with two different distances between the Si layers and plastics. The requirement for the thickness of the Si detector layers and its implication on the beta-detection efficiency has been investigated for 1 mm and 300 µm thickness of Si layers. The combined efficiency of DSSSD and plastic detectors were also simulated for two different thicknesses of the DSSSD.
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