Yvette Cauchois

Development and use of Synchrotron light Officer of the Legion of Honour Officers of the National Order of Merit (France) National Laboratories of Frascati Laboratory for the Use of Electromagnetic Radiation, Orsay University of Paris XI Yvette Cauchois (French pronunciation: [ivɛt koʃwa] ⓘ; 19 December 1908 – 19 November 1999) was a French physicist known for her contributions to X-ray spectroscopy and X-ray optics, and for pioneering European synchrotron research.

Cauchois undertook graduate studies at the Laboratory of Physical Chemistry with the support of a National Fund for Science studentship, and was awarded her doctorate in 1933 for her work on the use of curved crystals for high-resolution X-ray analysis.

[1] After completing her doctoral studies, Cauchois was appointed research assistant in the laboratory of Jean Perrin at the Centre national de la recherche scientifique (CNRS).

[2] When World War II broke out, Cauchois maintained continuity at the Laboratory, acting as Head of Studies when Jean Perrin had to flee to the United States.

[5] In the early 1930s, Cauchois established the fundamental principles of a new X-ray spectrometer that was both easy to use and had a high resolution, satisfying the Bragg reflection condition.

In 1936, Cauchois and Horia Hulubei claimed to have discovered element 85 via X-ray analysis, conducting further research and publishing on follow-up studies in 1939.

[1] After meeting a priest from the monastery of Bârsana in Maramureș, Romania and discussing religious themes with him, Cauchois decided to be baptized in the Orthodox religion at age 86.