Enrico Fermi : biography
To continue the research where it would not pose a public health hazard, the reactor was disassembled and moved to the Argonne site, where Fermi directed research on reactors and other fundamental sciences, revelling in the myriad of research opportunities that the reactor provided. The lab would become the Argonne National Laboratory on 1 July 1946, the first of the national laboratories established by the Manhattan Project. Fermi was on hand at Oak Ridge to watch the air-cooled X-10 Graphite Reactor go critical on 4 November 1943, allowing the reactor plutonium to be created.
In September 1944, Fermi inserted the first fuel slug into the B Reactor at the Hanford Site. Over the next few days, 838 tubes were loaded, and the reactor went critical. Shortly after midnight on 27 September, the operators began to withdraw the control rods to initiate production. At first all appeared well, but around 03:00, the power level started to drop and by 06:30 the reactor had shut down completely. The cooling water was investigated to see if there was a leak or contamination. The next day the reactor started again, only to shut down once more. The problem was traced to neutron poisoning from xenon-135, which has a half-life of 9.2 hours. As it happened, DuPont had deviated from the Metallurgical Laboratory’s original design in which the reactor had 1,500 tubes arranged in a circle, and had added an additional 504 tubes to fill in the corners. The scientists had originally considered this overengineering a waste of time and money, but Fermi realized that by loading all 2,004 tubes, the reactor could reach the required power level and efficiently produce plutonium.
In the summer of 1944, Robert Oppenheimer persuaded Fermi to join his Project Y in Los Alamos, New Mexico. Arriving in September, Fermi was appointed an associate director of the laboratory, with broad responsibility for nuclear and theoretical physics, and was placed in charge of F Division, which was named after him. F Division consisted of four branches: the F-1 Super and General Theory under Teller, which was responsible for the development of a thermonuclear "Super"; the F-2 Water Boiler under L. D. P. King, which looked after the "water boiler" research reactor; F-3 Super Experimentation under E. Bretscher; and the F-4 Fission Studies under Anderson. Fermi observed the Trinity test on 16 July 1945, and conducted an experiment using strips of paper to estimate the bomb’s yield. He came up with a figure of ten kilotons of TNT; the actual yield was about 18.6 kilotons.
Professor in Rome
Professorships in Italy were granted by competition () for a vacant chair, the applicants being rated on their publications by a committee of professors. Fermi applied for a chair of mathematical physics at the University of Cagliari at Cagliari on Sardinia, but was narrowly passed over in favour of Giovanni Giorgi. In 1926, at the age of 24, he applied for a professorship at the University of Rome. This was a new chair, one of the first three in theoretical physics in Italy, that had been created by the Minister of Education at the urging of Professor Orso Mario Corbino, who was the University’s professor of experimental physics, the Director of the Institute of Physics, and a member of Benito Mussolini’s cabinet. Corbino, who also chaired the selection committee, hoped that the new chair would raise the standard and reputation of physics in Italy. The committee chose Fermi ahead of Enrico Persico and Aldo Pontremoli, and Corbino helped Fermi recruit his team, which was soon joined by notable students such as Edoardo Amaldi, Bruno Pontecorvo, Ettore Majorana and Emilio Segrè, and by Franco Rasetti, whom Fermi had appointed as his assistant. They were soon nicknamed the "Via Panisperna boys" after the street where the Institute of Physics was located.
Fermi married Laura Capon, a science student at the University, on 19 July 1928. They had two children: Nella, born in January 1931, and Giulio, born in February 1936. On 18 March 1929, Fermi was appointed a member of the Royal Academy of Italy by Benito Mussolini, and on 27 April Fermi joined the Fascist Party. He would come to oppose Fascism, but only a decade later when it affected him personally.