Arthur Compton
Thomas attended a series of crisis meetings in Chicago with Connant, Groves, Arthur Compton, Kenneth Nichols and Enrico Fermi. It was agreed that the isotopes could not be separated, so high-purity plutonium would not be required. Thomas therefore decided to disband his plutonium purification team. The Los Alamos laboratory then turned to the technologically much more difficult task of building an implosion-type nuclear weapon.