Manhattan Project


Pupin Hall Exterior

In 1939 A team of Columbia professors including Fermi, Szilard, Eugene T. Booth and John Dunning , using a cyclotron (or “atom smasher”) located in the basement of Pupin Hall, demonstrated the first nuclear fission reaction in the Americas, verifying the work of Hahn and Strassmann.  In the decades that followed, Pupin Hall was the site of numerous foundational discoveries in nuclear research including measurement of the magnetic properties of the atomic Nuclei (Nobel prize awarded to I. Rabi 1944); first measurements of electron spin (Nobel prize awarded to W.E. Lamb and P. Kusch in 1955); development of theory and experiment that identified parity violation in the weak nuclear force (T.D. Lee was awarded the Nobel prize in 1955, and later C.-S. Wu received the Wolf prize in 1975); and development of the Maser-Laser principle (Nobel prize awarded to C. Townes in 1964).  The work by Dunning and colleagues would also lead to the Manhattan project, a government funded effort to develop nuclear weapons for World War II.  In 1966, the entire Pupin Physics Laboratories was named a  national landmark owing to the historic importance of the many significant discoveries made throughout the building.

A copy of the National landmark filing can be found here, and a draft of the press release, written at the time of the landmark designation, can be found here. Extensive documentation on the Pupin Physics Laboratories can also be accessed at the National Archives Catalog listing

Pupin Hall Uranium Experiments

Mr. Mori visits Pupin Hall

There are no plaques or markers, but in room 118 of Pupin Hall was a home to a famous magnet. This magnet was where the first isotope separation of Uranium was performed. The person who did the experiment is Dunning, his paper is published here. This article by H. L. ANDERSON,  E. T.Booth, J. R. DUNNING, E. FERMI, G. N. GIasoe, and F. G. SIack acknowledges funding from the Ernest Kempton Adams Fund for Physical Research of Columbia University.

Dunning Cyclotron

Dunning Cyclotron

The Dunning Cyclotron was a component of an early particle accelerator hosted in the basement of the Pupin Physics Laboratories. Further reading can be found on the National Museum of American History, along with more pictures.