Irène Joliot-Curie
In 1938, after the Nazi German "Anschluss" of Austria, Diel escaped to France and worked at the Sainte-Anne psychiatric hospital in Paris. Unfortunately, because he was a foreign national, he became imprisoned in the Gurs internment camp in southern France during World War II. After his release, he was able to join CNRS in 1945 with the backing of Einstein and Irène Joliot-Curie. At CNRS he worked as a children's psychotherapist in Henri Wallon's laboratory.