Soft X-ray absorption spectroscopy: reading an element's chemical ID
SXAS stands for Soft X-ray Absorption Spectroscopy. It belongs to the wider family of XAS, with the photon energy kept between roughly 50 eV and 2 keV. That window happens to cover: the K-edges of carbon, nitrogen, oxygen and fluorine (a 1s electron is excited); the L-edges of 3d transition metals (2p → 3d); some alkali and alkaline-earth edges. In other words, it is good at light elements and 3d metals — exactly the actors in battery materials, catalysts, polymers and biomolecules. The ab...
What a synchrotron is: turning electrons into a tunable torch
“Synchrotron radiation” sounds like nuclear physics, but the everyday picture is simpler: push electrons to almost the speed of light, then make them turn. Turning costs the electrons energy, and that energy leaves as light. The light spans infrared, ultraviolet and hard X-rays, and it is several orders of magnitude brighter than a laboratory X-ray tube. So a synchrotron is not a bigger X-ray machine. It is a whole facility — accelerator, storage ring and experimental stations chained togethe...