Kai Manne Borje Siegbahn
Siegbahn, Kai Manne Borje (1918-) is a Swedish physicist. He won a share of the 1981 Nobel Prize in physics for his contribution to the development of high-resolution electron spectroscopy, a technique for analyzing substances at the atomic level. Siegbahn shared the prize with the American physicists Nicolaas Bloembergen and Arthur Leonard Schawlow, who independently developed the related technique of laser spectroscopy.
Siegbahn was born on April 20, 1918, in Lund, Sweden. His father was Karl Manne Georg Siegbahn, winner of the 1924 Nobel Prize in physics for his work in X-ray spectroscopy. Kai Siegbahn studied physics, chemistry, and mathematics at the Uppsala University in Sweden, receiving a bachelor's degree in 1939 and a licentiate degree (the equivalent of a master's degree) in 1942. From 1942 to 1951, Siegbahn was a researcher at the Nobel Institute of Physics (now the Manne Siegbahn Laboratory). He received a doctoral degree from the University of Stockholm in 1944.
Siegbahn became a professor of physics at the Royal Institute of Technology in Stockholm in 1951. From 1954 until his retirement in 1984, he was a professor and then head of the physics department at Uppsala University.
Siegbahn did the work for which he won the Nobel Prize in the late 1940's, 1950's, and 1960's. He contributed to the development of high-resolution electron spectroscopy, a technique that bombards a substance with beams of X rays in order to observe the electrons (subatomic particles) released from the substance's inner layers of atoms as a result. Siegbahn found that the energy of the emerging electrons depends on the nature of the chemical bonds between the atoms. This form of high-resolution analysis became known as electron spectroscopy for chemical analysis (ESCA). Siegbahn wrote the books ESCA (1967) and ESCA Applied to Free Molecules (1969) to explain his technique.