Meitner

The isolation and identification of 4 radioactive elements in minute amounts took place at the turn of the century, and in each case the insight provided by the periodic classification into the predicted chemical properties of these elements proved invaluable. Marie Curie identified polonium in 1898 and, later in the same year working with Pierre Curie, isolated radium. Actinium followed in 1899 (A. Debierne) and the heaviest noble gas, radon, in 1900 (F. E. Dorn). Details will be found in later chapters which also recount the discoveries made in the present century of protactinium (O. Hahn and Lise Meitner, 1917), hafnium (D. Coster and G. von Hevesey, 1923), rhenium (W. Noddack, Ida Tacke and O. Berg, 1925), technetium (C. Perrier and E. Segre, 1937), francium (Marguerite Percy, 1939) and promethium (J. A. Marinsky, L. E. Glendenin and C. D. Coryell, 1945). 

Dr. H. Wollenberger Hahn-Meitner Institut Glienicker Str. 100 D-1000 Berlin 39 Germany... 

In 1938 Niels Bohr had brought the astounding news from Europe that the radiochemists Otto Hahn and Fritz Strassmann in Berlin had conclusively demonstrated that one of the products of the bom-bardmeiit of uranium by neutrons was barium, with atomic number 56, in the middle of the periodic table of elements. He also announced that in Stockholm Lise Meitner and her nephew Otto Frisch had proposed a theory to explain what they called nuclear fission, the splitting of a uranium nucleus under neutron bombardment into two pieces, each with a mass roughly equal to half the mass of the uranium nucleus. The products of Fermi s neutron bombardment of uranium back in Rome had therefore not been transuranic elements, but radioactive isotopes of known elements from the middle of the periodic table. 

In a 1959 lecture at Bryn Mawr College in Pennsylvania, Lise Meitner reflected that Life need not be easy, provided that it is not empty. Life was not easy for any Jewish woman scientist in Germany in the first half of the twentieth century, and Meitner certainly had her own experience in mind when she made this statement. 

Lise Meitner grew up in the Vienna of Emperor Franz-Josef and horsedrawn trolley cars. She was born there in 1878 into a well-to-do Jewish family and decided at an early age that she wanted to be a scientist like Madame Curie. (Later Albert Einstein would call her the German Madame Curie. ) In 1901, she entered the University of Vienna. There, where serious women students were considered odd, she was treated rudely by many of her fellow students. In 1905 she was only the second woman in the university s history to receive a Pli.D. in science. 

In 1907, she went to Berlin to study under Max Planck, promising her devoted parents that she would return to Vienna in six months at the most. She stayed in Berlin for thirty-one years. In Berlin, Meitner met Otto Flahn, a professor of chemistiy, and took an unpaid position assisting Flahn with his research on the chemistry of radioactive substances. At that time women were not allowed to v ork in the Chemical Institute, and she had to set up her laboratory in a carpenter s workshop outside the Institute. 

Wliile continuing work with Flahn at the new Kaiser Wilhelm Institute for Chemistry in Berlin-Dahlem, beginning in 1912 Meitner served as assistant to Max Planck at the Institute for Theoretical Physics at the University of Berlin, and in 1918 was appointed head of the physics department at the Kaiser-Wilhelm Institute. 

Tn their years together Hahn and Meitner did significant research on beta- and gamma-ray spectra. They discovered the new element protoactinium-91 and, at Meitner s suggestion, took up, and made great progress with, work on neutron bombardment of nuclei that Enrico Fermi had commenced in Rome. In 1938, this research was suspended when Adolph Hitler annexed Austria and Meitner had to flee Germany. 

Based on the strong recommendations of her German physics colleagues, Meitner received a research position in the Stockholm laboratory of Manne Siegbahn, the Swedish physicist who had received the 1924 Nobel Prize in Physics for his precision measurements on X-ray spectra. Siegbahn provided laboratory space for Meitner, but no suitable equipment for her to continue the research she had started in Berlin, and little encouragement for her work. 

Meitner was left very much to herself m the Stockholm Physics Institute, which had little... 

At the end of 1938, Hahn sent her a description of his experiments on the interaction of neutrons with uranium. He and a young chemist. Fritz Strasstnan. had detennined that one of the reaction products was clearly barium. Meitner was so excited about this that she showed Hahn s letter to her nephew, physicist Otto Frisch. Their discussions on the topic gave birth to the idea of nuclear fission. 

Frisch then demonstrated in his laboratory the tremendous release of energy accompanying fission, and a short paper by Meitner and Frisch in the British journal Natnrcin 1939 revealed the moinelitous concept of nuclear fission to the scientific world. It provided a new source of energy for the Earth, while at the same time introducing the possibility of a new weapon capable of tinbelicr able destructive power. 

The step from nuclear fission to a nuclear chain reaction and the atomic bomb was, in principle, quite straightfoiward. In practice, however, it consumed more time and money than was ever foreseen. Although it was her basic insight that eventually led to the fission bomb dropped on Hiroshima, Meitner refused to work on the bomb and, for humanitarian reasons, hoped that it would not work. 

When the question of the award of a Nobel Prize in Physics for the discovery of nuclear fission arose at the end of World War II, it was complicated by the fact that both Hahn and Strassmann were chemists. Another complication was that the Nobel Prize Committee had always considered radioactivity and radioactive atoms the responsibility of their chem-istiy committee—despite the fact that the discovery of fission had been interdisciplinai y from beginning to end. The Swedish Academy of Science was divided on whether the Chemistry Prize should be given jointly to Hahn and Meitner, or to Hahn alone. Finally they decided by a close vote to give the 1945 chemistry prize solely to Otto Hahn. 

The physics prize was still in question, and many nominators were strong in their support of Meitner as the recipient. She had continued to correspond with Hahn and advise him from afar on experiments to be... 

After the war, although now famous, Meitner continued her research in Stockholm, interrupted only by trips to receive honorary degrees and other scientific accolades. She shared in the prestigious Enrico Fermi Prize awarded by the U.S. Atomic Energy Committee in 1966. She retired to Cambridge, England, m 1960, to be near her nephew, Otto Frisch, and died there hi 1968 at the age of ninety. Like so many people all over the world during the Hitler period, Meitner s life had been far from easy, but no reasonable person would ever be tempted to call her life empty. 

Frisch, O. R. (1970). Lise Meitner. Biographical Memoirs of Fellows of the Royal Society 16 405-420. 

Meitner, L. (1964). Looking Back. Bnllctin of the Atomic Scientists 20 2-7. 

Sime, R. L. (1996). Lise Meitner A Life in Physics. Los Angeles University of California Press. 

Nuclear fission is a process in which a heavy nucleus—usually one with a nucleon number of two hundred or more—separates into two nuclei. Usually the division liberates neutrons and electromagnetic radiation and releases a substantial amount of energy. The discoveiyi of nuclear fission is credited to Otto I lahn and Fritz Strassman. In the process of bombarding uranium with neutrons in the late 1930s, they detected several nuclear products of significantly smaller mass than uranium, one of which was identified as Ba. The theorectical underpinnings that exist to this day for nuclear fission were proposed by Lise Meitner and Otto Frisch. Shortly after Hahn and Strassman s discovery. 

See also Electric Power, Generation of Environmental Problems and Energy Use Explosives and Propellants Meitner, Lise Military Energy Use, Historical Aspects of Molecular Energy Nuclear Energy Nuclear Energy, Historical Evolution of the Use of Nuclear Fission Fuel Nuclear Fusion Nuclear Waste. 

Enrico Fermi (Italian-American), Otto Hahn (German), F. Strassman, Lise Meitner (Austrian), and Otto Frisch (Austrian) discover and describe nuclear fission. 

The process of nuclear fission was discovered more than half a century ago in 1938 by Lise Meitner (1878-1968) and Otto Hahn (1879-1968) in Germany. With the outbreak of World War II a year later, interest focused on the enormous amount of energy released in the process. At Los Alamos, in the mountains of New Mexico, a group of scientists led by J. Robert Oppenheimer (1904-1967) worked feverishly to produce the fission, or atomic, bomb. Many of the members of this group were exiles from Nazi Germany. They were spurred on by the fear that Hitler would obtain the bomb first Their work led to the explosion of the first atomic bomb in the New Mexico desert at 5 30 a.m. on July 16,1945. Less than a month later (August 6,1945), the world learned of this new weapon when another bomb was exploded... 

Refs 1) Beil 17, 106, [105] 1015 la) W.J. Murlack et al, Polyglycidyl Nitrate-Part 1. . , NAVDRD Report 2028-Part 1, NOTS 685 (1953) lb) J.G. Meitner et al, Polyglycidyl Nitrate-Part 2. . NAVORD Report 2028-Part 2, NOTS 686 (1953)... 

Department of Solare Energetik, Hahn-Meitner Institute, Berlin, Germany... 

In 1938, Lise Meitner, Otto Hahn, and Fritz Strassmann realized that, by bombarding heavy atoms such as uranium with neutrons, they could split the atoms into smaller fragments in fission reactions, releasing huge amounts of energy. We can estimate the energy that would be released by using Einstein s equation, as we did in Example 17.5. 

Hahn-Meitner-Institut fur Kernforschung Berlin, Sektor Strahlenchemie, Berlin, West Germany... 

Hahn-Meitner-Institut Berlin Bereich Strahlenchemie, D-1000 Berlin 39, FRG... 

Lise Meitner was an Austrian-born physicist who worked in Germany. Because she was a woman, she was denied permission to work in the research lab and was relegated to the carpenter s workroom. Nevertheless, her hard work and diligent research earned the respect of her coworkers. When the Nazis took over, however, she was forced to flee to Sweden. 

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