In 1937, Wirtz became a staff scientist at the Kaiser-Wilhelm Institut für Physik, an institute under the Kaiser-Wilhelm-Gesellschaft and located in Dahlem-Berlin. In 1940, he worked on the horizontal layer reactor design with Fritz Bopp and Erich Fischer. In 1941, he also became a Privatdozent at the Humboldt University of Berlin. In 1944, Wirtz was appointed head of the experimental department at the KWIP, which had been moved to Hechingen in 1943 to avoid bombing casualties to the personnel. In late spring 1945, Wirtz was arrested by the allied British and American Armed Forces and incarcerated at Farm Hall for six months under Operation Epsilon. From 1946, Wirtz worked at the Max-Planck Institut für Physik, which was the renamed Kaiser Wilhelm Institute for Physics and had been opened in the British Occupation Zone in Göttingen. From 1948 to 1957, he was also an extraordinarius professor at the University of Göttingen. From 1950, he also became a scientific member of the Kaiser-Wilhelm-Gesellschaft. From 1957 to 1979, Wirtz was an ordinarius professor of physical foundations of reactor technology at the Technische Hochschule Karlsruhe and director of the Institute of Neutron Physics and Reactor Technology at the Center for Nuclear Research, which was established in 1957 in Karlsruhe. From 1965 to 1967, he was chairman of the scientific council of the Karlsruhe Center for Nuclear Research. From 1974 to 1976, he was dean of the faculty of mechanical engineering at Technische Hochschule Karlsruhe.
1972 - 1977: Member of the presiding committee of the Deutsches Atomforum.
Internal Reports
The following reports were published in Kernphysikalische Forschungsberichte, an internal publication of the German Uranverein. The reports were classified Top Secret, they had very limited distribution, and the authors were not allowed to keep copies. The reports were confiscated under the Allied Operation Alsos and sent to the United States Atomic Energy Commission for evaluation. In 1971, the reports were declassified and returned to Germany. The reports are available at the Karlsruhe Nuclear Research Center and the American Institute of Physics.
Erica Cremer and Karl Wirtz Untersuchungen des Schwerwassergehaltes einiger technischer Elektrolyseure in Deutschland G-21
Karl Wirtz Bericht II. Eine 10-stufige Elektrolyseuranlage zur Gewinnung von schwerem Wasser G-61
Werner Heisenberg, Fritz Bopp, Erich Fischer, Carl-Friedrich von Weizsäcker, and Karl Wirtz Messungen an Schichtenanordnungen aus 38-Metall und Paraffin G-162
Karl Wirtz Die elektrolytische Schwerwassergewinnung in Norwegen G-198
Karl Wirtz Einrichtung der Elektrolyse zur Aufbearbeitung von schwerem Wasser G-296
Fritz Bopp, Walther Bothe, Erich Fischer, Erwin Fünfer, Werner Heisenberg, O. Ritter, and Karl Wirtz Bericht über einen Versuch mit 1.5 to D2O und U und 40 cm Kohlerückstreumantel G-300
Selected Literature
Horst Korsching and Karl Wirtz Trennung von Flüssigkeitsgemischen mittels kombinierter Thermodiffusion und Thermosiphonwirkung: Methode von Clusius und Dickel, Naturwissenschaften Volume 27, Number 7, Page 110
Books
Horst Korsching and Karl Wirtz Trennung der Zinkisotope durch Thermodiffusion in flussiger Phase
Karl Heinrich Beckurts and Karl Wirtz Neutron Physics
Karl Winnacker and Karl Wirtz Das unverstandene Wunder: Kernenergie in Deutschland
Karl Winnacker and Karl Wirtz Atome Illusion ou Miracle?