Measurement of absolute E2 transition strengths in {sup 176}W: Signatures for a rapid shape change

Journal Article · Fri Oct 28 00:00:00 EDT 2011 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3628399· OSTI ID:21612072

Fransen, Ch; Dewald, A; Friessner, G; Hackstein, M; Jolie, J; Pissulla, T; Rother, W; Zell, K -O ^[1]; Moeller, O ^[2]

---

1. Institut fuer Kernphysik, Universitaet zu Koeln, Zuelpicher Strasse 77, 50937 Cologne (Germany)
2. Institut fuer Kernphysik, Technische Universitaet Darmstadt, Schlossgartenstrasse 9, 64289 Darmstadt (Germany)

The X(5) symmetry describes nuclei at the critical point of the shape phase transition from axially deformed rotor nuclei to spherical vibrators. {sup 150}Nd, {sup 152}Sm, and {sup 154}Gd were the first nuclei where the predicted characteristics of the X(5) symmetry were observed. Later it was shown that also {sup 176,178,180}Os can be successfully described with the X(5) symmetry.In the close vicinity of shape phase transitions one expects strongly changing nuclear shapes. In the X(5) region around A = 150 this was observed for nuclei with different neutron numbers, whereas in the X(5) region around A = 180 this is to be expected for different proton numbers. The aim of the work presented here is the confirmation of a rapid shape change for nuclei close to {sup 178}Os. Besides the knowledge on the level scheme of the nuclei of interest, especially absolute E2 transition strengths are crucial for the interpretation of nuclear structure. Prolate deformation is expected for {sup 176}W. Thus we performed a recoil distance Doppler shift (RDDS) measurement on {sup 176}W to measure E2 transition strengths from level lifetimes. The experiment was performed at the Cologne FN TANDEM accelerator with the Cologne coincidence plunger with the reaction {sup 169}Dy({sup 16}O,4n){sup 176}W and a beam energy of 80 MeV. We will present our experimental results and relate them to data on the neighboring nuclei {sup 178}Os and {sup 182}Pt. The results will be discussed in the framework of nuclear shape transitions in this mass region and compared to calculations with both the Interacting Boson Model (IBM) and the GCM.

• OSTI ID: 21612072
• Journal Information: AIP Conference Proceedings, Vol. 1377, Issue 1; Conference: FINUSTAR 3 Conference on frontiers in nuclear structure, astrophysics, and reactions, Rhodes (Greece), 23-27 Aug 2010; Other Information: DOI: 10.1063/1.3628399; (c) 2011 American Institute of Physics; 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
DOPPLER EFFECT
DYSPROSIUM 169
E2-TRANSITIONS
ENERGY LEVELS
GADOLINIUM 154
INTERACTING BOSON MODEL
LIFETIME
MEV RANGE
NEODYMIUM 150
NUCLEAR STRUCTURE
OSMIUM 178
OSMIUM 180
OXYGEN 16
PHASE TRANSFORMATIONS
PLATINUM 182
QUADRUPOLE MOMENTS
SAMARIUM 152
TUNGSTEN 176
ALPHA DECAY RADIOISOTOPES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
DYSPROSIUM ISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
ENERGY RANGE
ENERGY-LEVEL TRANSITIONS
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
GADOLINIUM ISOTOPES
HEAVY NUCLEI
HOURS LIVING RADIOISOTOPES
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
ISOTOPES
LIGHT NUCLEI
MATHEMATICAL MODELS
MINUTES LIVING RADIOISOTOPES
MULTIPOLE TRANSITIONS
NEODYMIUM ISOTOPES
NUCLEAR MODELS
NUCLEI
OSMIUM ISOTOPES
OXYGEN ISOTOPES
PLATINUM ISOTOPES
RADIOISOTOPES
RARE EARTH NUCLEI
SAMARIUM ISOTOPES
SECONDS LIVING RADIOISOTOPES
SHELL MODELS
STABLE ISOTOPES
TUNGSTEN ISOTOPES