0000000000185401
AUTHOR
J. Leske
Local suppression of collectivity in theN=80isotones at theZ=58subshell closure
) transition strengths [1] and thenumber of nucleons in the valence shell. The global behaviorof these quantities between the major shells as a function ofthe nucleon number is well understood in the frameworks ofboth collective and microscopic models. One could expect thatthese general trends in the collective properties between themajorshellsaremodulated bythesubshellstructure.However,it is usually thought that the pairing correlations with anenergy scale of about 2 MeV, smear out and dissolve thesubshell structure as long as the separation energies betweenthe subshells are only about a few hundred keV.The recently observed evolution of the isovectorquadrupole-collective valence-shell exc…
Local suppression of collectivity in the N=80 isotones at the Z=58 subshell closure
Background: Recent data on N=80 isotones have suggested that the proton π(1g7/2) subshell closure at Z=58 has an impact on the properties of low-lying collective states. Purpose: Knowledge of the B(E2;2+1→0+1) value of 140Nd is needed in order to test this conjecture. Method: The unstable, neutron-rich nucleus 140Nd was investigated via projectile Coulomb excitation at the REX-ISOLDE facility with the MINIBALL spectrometer. Results: The B(E2) value of 33(2) W.u. expands the N=80 systematics beyond the Z=58 subshell closure. Conclusions: The measurement demonstrates that the reduced collectivity of 138Ce is a local effect possibly due to the Z=58 subshell closure and requests refined theoret…
The Miniball spectrometer
The Miniball germanium detector array has been operational at the REX (Radioactive ion beam EXperiment) post accelerator at the Isotope Separator On-Line facility ISOLDE at CERN since 2001. During the last decade, a series of successful Coulomb excitation and transfer reaction studies have been performed with this array, utilizing the unique and high-quality radioactive ion beams which are available at ISOLDE. In this article, an overview is given of the technical details of the full Miniball setup, including a description of the γ-ray and particle detectors, beam monitoring devices and methods to deal with beam contamination. The specific timing properties of the REX-ISOLDE facility are hi…
AGATA-Advanced GAmma Tracking Array
WOS: 000300864200005