Beta-decay studies with laser-polarised beams of exotic nuclei

The goal of the BeLaPEx project is to study β decay of exotic nuclei relevant to the astrophysical r-process.

We will build the first European β-decay spectroscopy station dedicated to measurements with spin-polarised radioactive beams.

Our setup, DeVITO, will be coupled to the new beamline for laser-induced nuclear orientation, called Versatile Ion-Polarised Techniques Online (VITO).

We will apply a novel technique that utilises anisotropic β decay of spin-polarised nuclei, allowing to firmly assign spins and parities of excited states populated through allowed transitions based on the β-decay asymmetries measured in coincidence with the delayed radiations.

The BeLaPEx project will help to clarify the sensitivity of β-delayed neutron emission to the details of nuclear structure.

We will provide experimental data that can benchmark nuclear models and improve the understanding of β-delayed neutron emission.

The BeLaPEx project will be carried out at the Isotope Mass Separator On-Line facility (ISOLDE) at CERN, where a wide range of radioactive ion beams is available, including those relevant to the r-process.

The first part of the project will focus on the construction and commissioning of the DeVITO station allowing for measurements of β-particle, γ-ray and neutron emission from spin-polarised nuclei. Subsequently, we will start the physics program aimed at studying neutron-rich indium isotopes around N=82.

These nuclei are important for the r-process calculations since the A=130 peak in the r-process abundance pattern is linked to the closure of the N=82 shell.