Photo from the Nobel Foundation archive.
Charles Glover Barkla
Born: 7 June 1877, Widnes, United Kingdom
Died: 23 October 1944, Edinburgh, Scotland
Affiliation at the time of the award: Edinburgh University, Edinburgh, United Kingdom
Prize motivation: "for his discovery of the characteristic Röntgen radiation of the elements."
Charles Glover Barkla received his Nobel Prize one year later, in 1918.
Prize share: 1/1
Following the discovery of X-rays, it was soon established that an irradiated compound emitted secondary X-rays. In secondary spectra, lines appeared corresponding to different wavelengths. Around 1906, Charles Barkla showed that each element's secondary spectrum was unique, irrespective of temperature, structure, and chemical composition. Its spectrum was therefore a characteristic property of an atom and thus became an important tool in atomic research.