Search NASA⌕ Search

Engineering topics

Rasco, Charlie [ORNL]

Publications and source records attributed to Rasco, Charlie [ORNL].

Decay spectroscopy in the neutron-rich Mo–Ru–Pd region

A leading challenge of nuclear-structure research is to understand the properties of nuclides of extreme isospin. Experiments at radioactive-ion-beam facilities, such as the Facility for Rare Isotope Beams in the US, may answer key questions that address diverse topics including fundamental nuclear physics, stellar nucleosynthesis and nuclear applications. The neutron-rich Mo–Ru–Pd (Z = 42 – 46) nuclides are hypothesised to exhibit triaxial-oblate deformation. We performed an experiment with the Facility for Rare Isotope Beams Decay Station initiator (FDSi) to study the structure and decay properties of nuclides in this region. Over 100 different nuclides have been identified in a preliminary analysis of the data. This work presents a first look at several examples between Rb (Z = 37) and Ag (Z = 47). Performance of the FDSi and methods developed to measure ground-state and excited-state lifetimes are presented, and plans for future work are also discussed.

Allmond, James [ORNL] (ORCID:0000000165338721)↗

YSO implantation detector for beta-delayed neutron spectroscopy

A segmented-scintillator-based implantation detector was developed to study the energy distribution of β-delayed neutrons emitted from exotic isotopes. The detector comprises a 34 × 34 YSO scintillator coupled to an 8 × 8 anode Position-Sensitive Photo-Multiplier Tube (PSPMT) via a tapered light guide. The detector was used at RIBF, RIKEN for time-of-flight-based neutron spectroscopy measurement in the 78Ni region. The detector provides the position and timing resolution necessary for ion-beta correlations and time of flight measurements. The detector provides a high ~80% beta-detection efficiency and a sub-nanosecond timing resolution. This contribution discusses the details of the design, operation, implementation, and analysis developed to obtain neutron time-of-flight spectrum and the analysis methods in the context of neutron-rich nuclei in the 78Ni region.

Implantation detector↗