How do Barkla's ideas apply to modern X-ray technology?
My foundational work on characteristic X-rays and absorption edges is directly applied in modern X-ray fluorescence (XRF) spectrometers, which are used to identify elements in materials from archaeological artifacts to industrial alloys. The principle remains the same: a primary X-ray beam excites characteristic emissions from a sample, and the energies of those emissions reveal the elemental composition. My measurements of absorption coefficients also underpin medical X-ray imaging, where different tissues absorb X-rays based on their effective atomic number—a concept I helped establish. In security scanning, X-ray backscatter techniques rely on the scattering principles I studied. Even in particle physics, the K-series and L-series nomenclature I introduced is still used to describe atomic transitions. I am gratified that my insistence on letting the facts speak for themselves has provided such durable tools for science and society.
Ask Charles Glover Barkla the follow-up →