CERN Accelerating science

Experiments at CERN
Title	Seeking the purported magic number N= 32 with high-precision mass spectrometry
Author(s)	Grob, L K ; Schweikhard, L C ; Herfurth, F ; Boehm, C ; Manea, V ; Blaum, K ; Beck, D ; Kowalska, M ; Kreim, K D ; Stanja, J ; Audi, G ; Rosenbusch, M ; Wienholtz, F ; Litvinov, Y
Experiment	IS532
Greybook	See IS532 experiment
Approved	30 November 2011
Status	Completed on 30 April 2020
Collaboration	ISOLDE
Accelerator	CERN ISOLDE
Abstract	Accounting for the appearance of new magic numbers represents an exacting test for nuclear models. Binding energies offer a clear signature for the presence (or disappearance) of shell closures. To determine the strength of the purported N = 32 shell closure, we propose using the Penning-trap spectrometer ISOLTRAP for mass measurements of N = 34 isotones $^{58}$Cr (Z = 24), $^{55}$Sc (Z = 21) and $^{54}$Ca (Z = 20), as well as the N = 32 isotones $^{53}$Sc and $^{52}$Ca. We also propose measuring the mass of $^{60}$Cr to test the shell model prediction of a new magic number at N = 34. In addition to the Penning-trap system at ISOLTRAP, we intend to use the newly commissioned multi-reflection time-of-flight mass separator, which enables direct mass measurements on nuclei with half-lives below 50 ms.
Related document(s)	CERN-INTC-2011-053  (INTC-P-317)

Contact: Kreim, S W
Contact: Manea, V