Neon

Some ²¹Ne and ²²Ne form naturally in the Earth’s crust largely by reactions of ¹⁸O and ¹⁹F in minerals with neutrons and alpha particles emitted from uranium and thorium decay, called nucleogenic neon isotopes [29], [101]. In addition, neon isotopes can form at the surface of the Earth and in extraterrestrial bodies by cosmic-ray-induced spallation reactions on magnesium, silicon, aluminum, and sodium [103], [104]. Analyses of all three stable neon isotopes may be used to distinguish these sources from primordial neon. The relative amounts of atmospheric neon and crustal nucleogenic neon isotopes in deep groundwaters and natural gases have been used in studies of solid-water-gas interactions and migration (Fig. IUPAC.10.1). The cosmogenic component is mainly detected in ²¹Ne and can be used to determine cosmic-ray exposure ages of rock samples, including meteorites exposed during travel through space and boulders exposed by melting of glacial ice (Fig. IUPAC.10.1).

Masers (Microwave Amplification by Stimulated Emission of Radiation) containing ²⁰Ne have been used to study quantum physics. ²¹Ne may also play a role in maser studies of quantum physics [106].