On July 2, 1940, Enrico Fermi received U.S. Patent No. 2,206,634 on a process for the production of radioactive substances:

This patent on making radioactive elements through bombardment with slow moving neutrons, appears to be related to the work for which he won the 1938 Nobel Prize in physics. He would go on to earn thirteen more U.S. patents: U.S. Patent 2836554, “Air Cooled Neutronic Reactor,” issued April 1950; US Patent 2524379, “Neutron Velocity Selector,” issued October 1950; US Patent 2852461 “Neutronic Reactor”, issued September 1953; US Patent 2708656, “Neutronic Reactor”, issued May 1955; US Patent 2768134, “Testing Material in a Neutronic Reactor”, issued October 1956; US Patent 2780595, “Test Exponential Pile”, issued February 1957; US Patent 2798847, “Method of Operating a Neutronic Reactor”, issued July 1957; US Patent 2807581, “Neutronic Reactor”, issued September 1957; US Patent 2807727, “Neutronic Reactor Shield”, issued September 1957; US Patent 2813070, “Method of Sustaining a Neutronic Chain Reacting System”, issued November 1957; US Patent 2837477, “Chain Reacting System”, issued June 1958; US Patent 2931762, “Neutronic Reactor”, issued April 1960; US Patent 2969307, “Method of Testing Thermal Neutron Fissionable Material for Purity”, issued January 1961.

On a sad note, ten of these patents issued posthumously as Fermi died of cancer in 1954 at the age of 53 in November 1954. Apparently, Fermi always suspected that working near the nuclear pile involved great risk, yet he continued because he felt that the benefits outweighed the risks to his safety. Two of his graduate student assistants working near the nuclear pile also died of cancer.