Big Bang nucleosynthesis amounts of the hydrogen isotope deuterium (H or D), the helium isotope helium-3 (He), and a very small amount of the lithium isotope lithium-7 (Li). In addition to these stable nuclei, two unstable or radioactive isotopes were also produced: the heavy hydrogen isotope tritium (H or T); and the beryllium isotope beryllium-7 (Be); but these unstable isotopes later decayed into He and Li, as above. Essentially all of the elements that are heavier than lithium were created much later, by stellar nucleosynthesis in evolving and exploding stars. There are several important characteristics of Big Bang nucleosynthesis (BBN): The key parameter
On-Line Isotope Mass Separator On-Line Isotope Mass Separator The On-Line Isotope Mass Separator, also known as the ISOLDE Radioactive Ion Beam Facility, is a facility located at CERN on the PS Booster. It started operating in 1967 and was rebuilt twice with major upgrades in 1974 and 1992. ISOLDE (Isotope Separator On Line DEtector) is dedicated to producing radioactive nuclei for a number of applications covering nuclear, atomic, molecular and solid-state physics, but also biophysics and astrophysics. The large variety of available species allows the systematic study of atomic and nuclear properties and exotic decays far from the line of stability. As of 2006,