Nier, Alfred O. (Alfred Otto), 1911-1994

Alternative names
Birth 1911-05-28
Death 1994-05-16

Biographical notes:

Physicist. Died 1994.

From the description of An account of the first sample of separated Uranium 235 at the University of Minnesota in 1940, 1954. (Unknown). WorldCat record id: 82028106

Alfred Otto Carl Nier, world-renowned physicist and scientific instrument designer, was born in St. Paul, Minnesota, on May 28, 1911. He spent most of his career at the University of Minnesota, both as a student and as a member of the faculty. His post-doctoral work was done at Harvard University. He was chair of the Physics Department at the University of Minnesota from 1953-1965. Nier retired in 1980, though he continued his research work full-time. Nier died on May 16, 1994, from injuries suffered in an automobile accident on the way home from his laboratory.

From the description of Alfred O.C. Nier papers, 1930-1996. (University of Minnesota, Minneapolis). WorldCat record id: 62692969

Alfred Otto Carl Nier, world-renown physicist and scientific instrument designer, was born in St. Paul, Minnesota, on May 28, 1911. The son of German immigrants, he became interested in science at an early age and experimented with radios during his years as a student at Humboldt High School where he graduated in 1927.

With the exception of two brief periods totaling less than five years, Nier spent his entire career at the University of Minnesota. He enrolled in 1927 at the age of sixteen and received a B. S. Degree in electrical engineering in 1931. Nier commuted to the University on the street car, traveling from the far side of St. Paul. In his sophomore year he was singled out by Physics Department chair Henry Erikson after Nier scored one hundred percent on his first three physics quizzes. In the poor employment environment of the Great Depression, Nier opted for graduate school and received a M. S. in electrical engineering in 1933 and a Ph. D. in physics in 1936.

The modest Nier always maintained that he was often " the right place at the right time." While a doctoral student he worked as a teaching assistant and came under the tutelage of Professor John Tate, nationally-known physicist and editor of The Physics Review. Nier began working with an early version of the mass spectrometer, the instrument that became the essence of his professional life. He incorporated the work that had gone before him and created the highest resolution instrument anywhere in the world. From this point on Nier dominated the field of mass spectrometry until his death in 1994. His doctoral work led him to the first quantitative measurement of argon isotopes and to the discovery of the potassium 40 isotope in the spring of 1935.

The potassium discovery was significant in his receiving a two-year National Research Council post doctoral fellowship which he carried out at Harvard University. There Nier continued to work with the mass spectrometer and abundance of isotopes research. He was particularly interested in geochronology and the decaying of uranium isotopes to form lead.

Nier returned to Minnesota in 1938 to an assistant professor appointment in the Department of Physics. Harvard allowed him to keep his mass spectrometer tubes, and he assembled a new instrument. At the American Physical Society meeting in Washington in the spring of 1939 Nier's friend, Columbia University Professor John R. Dunning, introduced him to recent Nobel Prize winner Enrico Fermi, who encouraged Nier to use his mass spectrometer in the quest to determine which uranium isotope was responsible for slow neutron fission.

When Nier had not produced any results by October, Fermi wrote Nier the now-famous letter suggesting that the mass spectrometer was "...the best way to decide the question, which is of considerable theoretical and possibly practical interest."

Nier took Fermi's advice; and on February 29, 1940, mailed to Dunning for verification the minuscule samples that demonstrated that uranium 235 was the fissionable isotope. Nier's mentor, Professor Erikson, noted this research in his journal and observed with rather incredible understatement," This gave rise to a great interest."

Nier's U235 discovery placed him within a highly-charged scientific and political atmosphere, and by the end of 1940 his work had become classified. By the summer of 1942 the University had relieved him of teaching duties so that he could concentrate on research financed by the U. S. Government's Office of Scientific Research and Development. Together with his talented technician, Rudolph (Buddy) Thorness, Nier built seven more mass spectrometers for uranium analysis and nine for hydrogen-deuterium analysis. He also designed and built four instruments to be used as helium leak detectors. One of the leak detectors became the General Electric prototype for the manufacture of hundreds of machines crucial to the Manhattan Project during World War II.

Between the summer of 1943 and the fall of 1945 Nier worked on the Manhattan Project at the Kellex Corporation in laboratories located in the vicinity of Columbia University and his friend Dunning and another well-known Manhattan Project scientist, Eugene Booth. Kellex built the gas diffusion plant at Oak Ridge, Tennessee, to collect the U235 used in the atomic bomb. Nier designed the mass spectrometers for process control at the plant.

After Nier returned to Minnesota in the fall of 1945, he assumed a heavy teaching load; but he also continued to develop mass spectrometers and to revolutionize atomic measurement. His research focused on measuring the atomic masses of most of the elements in the periodic table. He applied his instrumentation to other fields--geology, meteorology, and medicine. Together with Edgar Johnson he developed a double-focusing mass spectrometer which became famous for its Johnson-Nier geometry.

The University of Minnesota promoted Nier to full professor in 1944; and after he spent a brief period as acting chair he became Chair of the Physics Department in 1953, serving until 1965. In this role he concentrated on hiring outstanding faculty and on improving science education in the public schools. In 1965 the University appointed Nier a Regents' Professor, the highest honor bestowed upon a faculty member. Nier also participated in the University Senate and its committees. In 1966-1967 he chaired the Senate Consultative Committee in its search for a new University President. During this period he also traveled extensively, many times to laboratories in foreign countries.

During the late Fifties Nier became acquainted with Rudolph Bieri and Peter Signer, two European scientists who came to the University of Minnesota as postdoctoral researchers. They stirred Nier's interest in meteorite research. From meteorites he progressed to space science, a focus that continued for thirty-five years.. Beginning in 1960 he became active on committees of the National Academy of Sciences, Space Sciences Board. In 1964, working with the Naval Research Laboratory, he began experiments with Aerobee Rockets and developed small mass spectrometers for upper atmosphere analysis.

Nier's grants from the National Aeronautics and Space Administration led to the development of prototype instruments for the Viking Mars and Pioneer Venus missions. Under a NASA contract in the early Seventies he developed instruments and performed data processing for the Atmospheric Explorer Satellites C, D, and E.

In 1970 NASA selected Nier to head the Entry Science Team for the Viking mission to Mars. When the Viking lander set down on July 20, 1976, a Nier-designed mass spectrometer detected the presence of argon and nitrogen in the Martian atmosphere, a significant discovery of the mission. Nier also served as a member of the Molecular Analysis Team in the Viking program.

Simultaneous with his intense research activities Nier was active on several national boards. He was appointed to the National Bureau of Standards Panel for the Analytical Chemistry Division. He chaired the National Research Council Board of Fellowships and Associateships and served on the editorial board of Science, published by the American Association for the Advancement of Science. The National Academy of Sciences named Nier to chair an ad hoc committee, requested by the U. S. Arms Control and Disarmament Agency. The committee operated as a workshop; and on October 4, 1975, issued its report entitled "Long-Term Worldwide Effects of Multiple Nuclear-Weapons Detonation." The cautious optimism of the report stirred considerable controversy in the press.

Nier also participated in a number of international programs including COSPAR, the Committee on Space Research established by the International Council of Scientific Unions, and COESA, the Committee on Extension of the Common Atmosphere. Working with the Atomic Weights Commission, the International Union of Pure and Applied Chemistry (IUPAC), and the International Union of Pure and Applied Physics (IUPAP), Nier became a principal promoter of the successful efforts to establish Carbon 12 as the common standard for measurements in chemistry and physics.

Professional memberships also demonstrate Nier's devotion to scientific endeavor. The focus of his participation varied with his changing research interests; and he became involved in a number of organizations including the American Society for Mass Spectrometry, the Geochemical Society, the Geological Society of America, the American Geophysical Union, the American Vacuum Society, Sigma XI, and the Meteoritical Society.

Nier officially retired from the University of Minnesota in 1980; but he continued a full-time research program, working closely with his assistant, Dennis Schlutter. Nier's research interests shifted once again, this time to extraterrestrial materials; and he conducted many mass spectrometer experiments to analyze interplanetary dust particles, also known as cosmic dust. He continued to maintain his many professional contacts and his attendance at conferences. Nier died on May 16, 1994, from injuries suffered in an automobile accident on the way home from his laboratory. Just a few days shy of his eighty-third birthday, he was still under contract with the Los Alamos National Laboratory. During Nier's sixty-year career his intense curiosity and persistent hard work drove him to contribute 218 publications to refereed journals and to design countless mass spectrometers.

Throughout his long career Nier collected many honors and awards. He was elected to the National Academy of Sciences in 1950 and to the American Philosophical Society in 1953. In 1956 the Geological Society of America awarded him its Arthur L. Day Medal for his work with geochronology. In 1959 he was elected as a Foreign Scientific Member of the Max-Planck Institute for Chemistry (Otto Hahn Institute) in West Germany. NASA honored him twice--with a Medal for Exceptional Scientific Achievement in 1977 and a posthumous Public Service Medal in 1995. In 1980 he was elected to the American Academy of Arts and Sciences and to the Royal Swedish Academy of Science. He won the Geochemical Society's Viktor M. Goldschmidt Medal in 1984, the American Chemical Society's Field and Franklin Award in 1985, the International Mass Spectrometry Conference's Thomas Medal in 1985, and the American Geophysical Union's William Bowie Medal in 1992. In 1995 the Commission on New Minerals and New Mineral Names of the International Mineralogical Association honored Nier posthumously by designating "Nierite" as a new trigonal silicon nitride.

From the guide to the Alfred O.C. Nier papers, 1930-1996, (University of Minnesota Libraries. University of Minnesota Archives [uarc])


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Ark ID:


  • Atmosphere--Research
  • Patents
  • Spectrometer
  • Aerobee rocket
  • Interplanetary dust
  • Potassium--Isotopes--Spectra
  • Nuclear energy
  • Mass spectrometers
  • Teaching--Aids and devices
  • Meteorites
  • Viking rockets
  • Radiocarbon dating
  • Cosmic dust
  • Venus probes
  • Isotope separation
  • Geological time
  • Uranium--Spectra
  • Scientific apparatus and instruments--Designs and plans
  • Mass spectrometry
  • Uranium
  • Leak detectors


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  • Oak Ridge (Tenn.) (as recorded)
  • Churchill (Man.) (as recorded)
  • Oak Ridge (Tenn.) (as recorded)
  • Churchill (Man.) (as recorded)