Speaker
Description
By introducing spin polarisation into β-decay studies, one can overcome the difficulty of conventional β-decay spectroscopy to firmly determine the spins and parities of nuclear states involved in allowed transitions. This is because the sign and degree of asymmetry in β-decay from polarised nuclei depends on the spin difference between the initial and final states.
This novel approach to β-decay experiments, pioneered by a group from the University of Osaka [1,2], has been recently adopted at the VITO beamline [3], where a new decay-spectroscopy station, called “DeVITO”, has been implemented, allowing thus for measurements of β-emission asymmetry in coincidence with γ-rays and/or neutrons.
The new setup was commissioned with beams of neutron-rich potassium isotopes, including strong β-delayed neutron emitters 49K and 51K [4]. In particular, measurements with a 47K beam successfully demonstrated DeVITO’s capability to measure β–decay asymmetry in coincidence with γ-rays and its use for the determination of spin values for excited states populated in daughter nuclei.
In this contribution, details on the new experimental setup, as well as preliminary results obtained for 47K and 49K [4] will be presented, including β-particle emission asymmetry measured in coincidence with γ-rays following the 47K β decay.
[1] H. Miyatake et al., Phys. Rev. C 67, 014306 (2003).
[2] H. Nishibata et al., Phys. Rev. C 99, 024322 (2019).
[3] M. Kowalska et al., Phys. G: Nucl. Part. Phys. 44, 084005 (2017).
[4] M. Piersa-Silkowska, M. Madurga, M. Kowalska et al., CERN-INTC-2023-026, INTC-P662 (2023).
