- Person
- Lise Meitner
- Lived
- 1878–1968
- Field
- Physics
- From
- Austrian-Swedish
The story
In the early 1920s Lise Meitner, head of her own physics section at the Kaiser Wilhelm Institute for Chemistry in Berlin, was studying beta radiation, the electrons given off by radioactive nuclei. A long-running puzzle surrounded these electrons. Some appeared in sharp lines of particular energies, while others formed a continuous spread, and physicists, including the British scientist James Chadwick, disagreed about where each kind came from.
In 1921 Meitner accepted an invitation from Manne Siegbahn to lecture on radioactivity as a visiting professor at Lund University in Sweden. Siegbahn's laboratory was a leader in X-ray spectroscopy, and Meitner was eager to learn the technique. There she also met the Dutch doctoral student Dirk Coster, who years later would help her escape from Nazi Germany.
Armed with this new knowledge, she took a fresh look at the beta-ray spectra when she returned to Berlin, examining lead-210, radium-226 and thorium. In 1922 she discovered the cause of electrons being emitted from atoms with characteristic, signature energies. When an inner electron is removed from an atom, an electron from a higher level drops into the vacancy. The energy released can then knock out a second electron from the same atom instead of escaping as a particle of light. The French physicist Pierre Auger discovered the process independently in 1923, while analysing cloud chamber photographs, and for decades it carried only his name.
Today the process is increasingly called the Auger-Meitner effect, recognising Meitner's priority. The same year she became the first woman to receive the habilitation, the qualification to teach at university, in physics in Prussia, and by 1926 she was a professor. Her section at the Kaiser Wilhelm Institute became a magnet for physicists from Germany and around the world, who came to Berlin to conduct research under her supervision.
The effect has proved remarkably useful. Because the energies of the ejected electrons depend on the type of atom and its chemical surroundings, Auger electron spectroscopy can identify which elements are present at a material's surface. The effect also matters in medicine and biology, where Auger electrons released inside cells can damage DNA, a property studied for targeted cancer treatments known as Auger therapy.
Why it matters
The Auger-Meitner effect underlies Auger electron spectroscopy, a standard technique for analysing the chemical make-up of surfaces in materials science.
About Lise Meitner
Nuclear physicist who co-discovered nuclear fission; refused to work on the atomic bomb. Element 109 (meitnerium) named for her.
More about Lise Meitner
- Lise Meitner explained and named nuclear fissionLise Meitner and her nephew Otto Frisch were the first to explain how a uranium nucleus splits, and in a 1939 paper in Nature they named the process "fission".
- Lise Meitner became Germany's first woman physics professorIn 1926 Lise Meitner became the first woman university professor of physics in Germany, after starting her Berlin career as an unpaid guest in a converted woodshop.
- Lise Meitner isolated and named protactiniumWorking almost alone during the First World War, Lise Meitner isolated the long-lived isotope of element 91 by December 1917 and named the element protactinium.
- Lise Meitner refused to help build the atomic bombAlthough her work explained nuclear fission, Lise Meitner declined an invitation to join the British mission to the Manhattan Project, saying she would have nothing to do with a bomb.
- Lise Meitner served as an X-ray nurse in World War IDuring the First World War, Lise Meitner trained as an X-ray technician and served with the Austrian Army as an X-ray nurse on the Eastern and Italian fronts.
Sources
- Lise Meitner Wikipedia
- Auger effect Wikipedia
Another act of tikkun olam. This is part of tikkun olam, the Jewish idea of repairing the world, and every one of us can add to it.