Extreme ultraviolet light (EUV light) does not naturally occur on Earth, but it can be produced. In nanolithography machines, EUV light is generated using an immensely hot tin plasma. Researchers at ARCNL, in close collaboration with the American Los Alamos National Laboratory, have unraveled how such a plasma emits EUV light at the atomic level, and have made unexpected discoveries, reporting that all excited energy states of tin were found to have the right energy to emit EUV light. The researchers published their findings in Nature Communications on May 11.
Source:
https://phys.org/news/2020-05-exceptional-euv-hot-tin-plasma.html