Precision lifetime measurements of exotic nuclei based on Doppler-shift techniques

Journal Article · Fri Apr 19 00:00:00 EDT 2013 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.4802395· OSTI ID:22117014

Iwasaki, Hironori ^[1]

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1. National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States) and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan (United States)

A recent progress in precision lifetime measurements of exotic nuclei at the National Superconducting Cyclotron Laboratory (NSCL), Michigan State University is presented. The Recoil Distance Doppler-shift (RDDS) technique has been applied to nuclear reactions involving intermediate-energy rare isotope (RI) beams, to determine absolute transition strengths between nuclear states model independently from level lifetimes of interest. As such an example, recent lifetime measurements of the first 2{sup +} states in the neutron-rich {sup 62,64,66}Fe isotopes at and around N=40 are introduced. The experiment was performed at the Coupled Cyclotron Facility at NSCL using a unique combination of several experimental instruments; the Segmented Germanium Array (SeGA), the plunger device, and the S800 spectrograph. The reduced E2 transition probabilities B(E2) are determined directly from the measured lifetimes. The observed trend of B(E2) clearly demonstrates that an enhanced collectivity persists in {sup 66}Fe despite the harmonic-oscillator magic number N=40. The present results are also discussed in comparison with the large-scale shell model calculations, pointing to a possible extension of the deformation region beyond N=40.

• OSTI ID: 22117014
• Journal Information: AIP Conference Proceedings, Vol. 1525, Issue 1; Conference: 22. international conference on application of accelerators in research and industry, Ft. Worth, TX (United States), 5-10 Aug 2012; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
COLLECTIVE MODEL
COMPARATIVE EVALUATIONS
DEFORMED NUCLEI
DOPPLER EFFECT
DSA METHOD
E2-TRANSITIONS
GE SEMICONDUCTOR DETECTORS
HARMONIC OSCILLATORS
IRON 62
IRON 64
IRON 66
LIFETIME
NEUTRONS
NUCLEAR DEFORMATION
NUCLEAR REACTIONS
PROBABILITY
RADIOACTIVE ION BEAMS
RECOILS
SHELL MODELS
SUPERCONDUCTING CYCLOTRONS