High-sensitivity study of levels in Al 30 following β decay of Mg 30

Open Access

Abstract

B. Olaizola et al. ; 7 págs.; 5 figs.; 1 tab. ; Open Access funded by Creative Commons Atribution Licence 3.0 ; γ-ray and fast-timing spectroscopy were used to study levels in Al30 populated following the β- decay of Mg30. Five new transitions and three new levels were located in Al30. A search was made to identify the third 1+ state expected at an excitation energy of ∼2.5 MeV. Two new levels were found, at 3163.9 and 3362.5 keV, that are firm candidates for this state. Using the advanced time-delayed (ATD) βγγ(t) method we have measured the lifetime of the 243.8-keV state to be T1/2=15(4)ps, which implies that the 243.8-keV transition is mainly of M1 character. Its fast B(M1;2+→3+) value of 0.10(3) W.u. is in very good agreement with the USD shell-model prediction of 0.090 W.u. The 1801.5-keV level is the only level observed in this study that could be a candidate for the second excited 2+ state. Published by the American Physical Society ; Fast-timing detectors and electronics were provided by the Fast Timing Collaboration. This work was supported in part by the Spanish MINECO through the FPA2013-41467-P, FPA2015-64969-P, and FPA2015-65035-P projects, Grupo de Física Nuclear (GFN) at UCM and by the NuPNET network FATIMA via the PRI-PIMNUP-2011-1338 project. Support by the European Union Sixth Framework Programme through RII3-EURONS (Contract No. 506065) is acknowledged. ; Peer Reviewed