Friday

Theoretical predictions and former experiments on fully-stripped ions have shown that the ionization state can dramatically modify, even of several orders of magnitudes, β-isotopes lifetimes (e.g. by bound state β-decay). In the framework of the PANDORA project, a new experimental method aims at measure, for the first time, nuclear β-decays lifetimes in magnetically confined plasmas. PANDORA will allow the online investigation of β–decay probabilities in a stellar-like scenario (as concern, mainly, the charge state distribution (CSD)), correlating the influence of the CSD and the other parameters (plasma density and temperature) on the in-plasma lifetime. This approach is expected to have a major impact in the study of nuclear astrophysics processes (BBN, s-processes, Cosmo Chronometers, Early Solar System formation) in order to better reveal the pathways of stellar nucleosynthesis and, thus, improving the understanding of the origin and the abundances of the elements in the Universe. An innovative design of a high-performance ECR plasma trap, in combination with a plasma multi-diagnostics setup working synergically with a γ-rays detection system to tag the in-plasma nuclear decays, has been developed and the radionuclides can be maintained in a dynamical equilibrium for several days or even weeks. The experimental method and the preliminary results concerning simulations of a virtual experimental run, performed to study the feasibility of measuring the decay rates of several nuclei in the PANDORA trap, will be hereby discussed. Among the first physical cases selected for the phase-1, there are nuclei involved in s-processing nucleosynthesis: 134Cs, 94Nb, 176Lu. This contribution reports in particular about the in-plasma predicted lifetimes with a sensitivity study in terms of 3-sigma-level of confidence: results indicate that experimental runs should take several days to 3 months, depending on the isotope under investigation, thus shading new light on the role of weak interaction on the stellar nucleosynthesis.