Atomic Heritage Foundation

In partnership with the National Museum of Nuclear Science & History National Museum of Nuclear Science & History

Join Today as an Atomic History Patron Member

1942 to 1943: Early Manhattan Project

1942 to 1943: Early Manhattan Project

Timeline Image: 
Chicago Pile Argonne

1943 Aug

Due to lagging progress on gaseous diffusion, and continuing uncertainties about the required amount of U-235 for a bomb, General Leslie Groves decides to double the size of the Y-12 Plant.

1943 Aug

Despite the efforts of more than 1000 researchers at Kellex and Columbia University, no suitable gaseous diffusion barrier material has yet been developed.

1943 June 24

Working with cyclotron produced plutonium, Emilio Segre determines that the spontaneous fission rate is 5 fissions/kg-sec. This is well within the assembly speed capability of a high speed gun.

1943 April 20

A contract is concluded with the University of California to manage Los Alamos, NM acting as paymaster, accountant, and procurement agency. This contract (back dated to Jan. 1 for work already performed) served as the basis for University of California management of both the Los Alamos and Lawrence Livermore laboratories.