Meitner, Lise (1878-1968)

Austrian-born Swedish physicist who worked with German radiochemist Otto Hahn and was the first to realize that they had inadvertently achieved the fission of uranium. They also discovered protactinium 1918. She refused to work on the atom bomb. Meitner was born in Vienna and studied there and at Berlin. She joined Hahn to work with him on radioactivity at the Kaiser Wilhelm Institute for Chemistry, but their supervisor Emil Fischer would not allow Meitner to work in his laboratory because she was a woman, and they had to set up a small laboratory in a carpenter's workroom. Nonetheless, Meitner was made joint director of the institute with Hahn 1917 and was also appointed head of the Physics Department. In 1912, Meitner had also become an assistant to Max Planck at the Berlin Institute of Theoretical Physics, and she was made professor at Berlin 1926. But in 1938 she was forced to leave Nazi Germany, and soon found a post at the Nobel Physical Institute in Stockholm. In 1947, a laboratory was established for her by the Swedish Atomic Energy Commission, and she later worked on an experimental nuclear reactor. During the 1920s, Meitner studied the relationship between beta and gamma irradiation. She was the first to describe the emission of Auger electrons, which occurs when an electron rather than a photon is emitted after one electron drops from a higher to a lower electron shell in the atom. In 1934 Meitner began to study the effects of neutron bombardment on uranium with Hahn. It was not found until after Meitner had fled from Germany that the neutron bombardment had produced not transuranic elements, as they expected, but three isotopes of barium. Meitner and her nephew Otto Frisch realized that the uranium nucleus had been split; they called it fission. A paper describing their analysis appeared 1939. Meitner continued to study the nature of fission products. Her later research concerned the production of new radioactive species using the cyclotron, and also the development of the shell model of the nucleus.