The PANDORA project: an experimental setup for measuring in-plasma β-decays of astrophysical interest

Experiments performed on Storage Rings have shown that lifetimes of beta-radionuclides can change dramatically as a function of the ionization state. PANDORA (Plasmas for Astrophysics, Nuclear Decay Observation and Radiation for Archaeometry) aims at measuring, for the first time, nuclear beta-decay rates in stellar-like conditions, especially for radionuclides involved in nuclear-astrophysics processes (BBN, s-processing, CosmoChronometers, Early Solar System formation). Compact magnetic plasma traps, where plasmas reach density n(e)similar to 10(11)-10(14) cm(-3), and temperature T-e similar to 0.1-30 keV, are suitable for such studies. The decay rates can be measured as a function of the charge state distribution of the in-plasma ions. The collaboration is now designing the plasma trap able to reach the needed plasma densities, temperatures and charge states distributions. A first list of radioisotopes, including tens of physics cases of potential interest is now available. Possible physics cases include, among the others, Tl-204, Ni-63, Co-60, Tm-171, Pm-147, Kr-85, Lu-176 and the pairs Re-187-Os-187 and Sr-87-Rb-87, which play a crucial role as cosmo-clock. Physics cases are now under evaluation in terms of lifetime measurements feasibility in a plasma trap.