Hans Jensen, Physiker und Nobelpreisträger

Hans Jensen came from very modest circumstances, but his exceptional talent made an academic career possible. After being appointed lecturer in Hamburg, he was called to Hanover in 1941 and to Heidelberg in 1948. Until completing his Habilitation, Jensen worked on the quantum-mechanical many-body problem before turning to nuclear physics. There he focused in particular on the question of the stability—and thus the abundance—of elements and their isotopes. For his answer to these questions, the nuclear shell model, he was awarded the Nobel Prize in 1963. Because Jensen’s scientific career unfolded during the National Socialist era, outstanding achievements in research and teaching alone were not enough to secure a successful university career. In 1937, he joined the Nazi Party, a step he took on the recommendation of two full professors he held in particularly high esteem. He was also afforded protection through his work on the uranium project of German nuclear physicists, which was classified as essential to the war effort. In 1943, Jensen shared his extensive knowledge of the state of this highly secret project with a group of Norwegian colleagues during a colloquium in Oslo. Jensen’s role between opportunism and resistance is presented here in detail for the first time, drawing also on newly uncovered archival records.