Scientists resolve uncertainty in stellar strontium formation

An international research team has conducted the first experimental investigation into a nuclear physics reaction critical to understanding how strontium is formed in stars. The study, involving institutions in the US, Canada, and Europe, utilized facilities such as the Argonne Tandem Linac Accelerator System (ATLAS) and the Facility for Rare Isotope Beams (FRIB).

By using indirect experimental techniques, researchers measured the neutron-capture rate of the isotope krypton-88. This measurement reduced the uncertainty of the rate from a factor of eight to approximately a factor of three. The findings revealed that the actual rate of neutron capture by krypton-88 is lower than previous theoretical predictions.

When these new rates were applied to the intermediate neutron-capture process (i-process) model, the predicted abundance of strontium increased. This adjustment brings scientific simulations into much closer agreement with actual astronomical observations of old stars, helping to resolve long-standing discrepancies in nucleosynthesis models.