CERN Accelerating science

Experiments at CERN
Title	Shape determination in Coulomb excitation of $^{72}$Kr
Author(s)	Butler, P ; Reiter, P ; Kruecken, R ; Paul, E S ; Wadsworth, R ; Heenen, P
Experiment	IS478
Greybook	See IS478 experiment
Approved	05 December 2008
Status	Completed on 04 May 2020
Collaboration	ISOLDE
Accelerator	CERN ISOLDE
Abstract	Nuclei with oblate shapes at low spins are very special in nature because of their rarity. Both theoretical and experimental shape co-existence studies in the mass 70 region for near proton drip-line nuclei suggest $^{72}$Kr to be the unique case with oblate low-lying and prolate high-lying levels. However, there is no direct experimental evidence in the literature to date for the oblate nature predicted for the first 2$^+$ state in $^{72}$Kr. We propose to determine the sign of the spectroscopic quadrupole moment of this state via the re-orientation effect in a low-energy Coulomb excitation measurement. In the inelastic excitation of the 2$^+$ state in $^{72}$Kr beam of 3.1 MeV/u with an intensity of 800 pps at REX-ISOLDE impinging on $^{104}$Pd target, the re-orientation effect plays a significant role. The cross section measurement for the 2$^+$ state should thus allow the model-independent determination of the sign of the quadrupole moment unambiguously and will shed light on the co-existing prolate and oblate shapes in this region
Related document(s)	CERN-INTC-2007-016  (INTC-P-228)

Contact: Clement, E
Contact: Van de walle, J