First Nuclear Chain Reaction Achieved
On December 2, 1942, a pivotal moment in scientific history occurred when the first sustained nuclear chain reaction was successfully achieved at the University of Chicago, led by Italian physicist Enrico Fermi. This groundbreaking achievement was built upon earlier discoveries in the 1930s, when scientists Otto Hahn and Fritz Strassman first identified the fission of uranium atoms through neutron bombardment. The theoretical groundwork for a chain reaction was laid by Leo Szilard, who envisioned the possibility of creating immense energy through controlled nuclear reactions. The urgency of the project intensified with the onset of World War II and concerns over Nazi Germany's potential nuclear capabilities, prompting President Franklin D. Roosevelt to initiate the Manhattan Project.
Fermi and his team constructed a reactor known as Chicago Pile Number One (CP-1), utilizing Uranium-235 and graphite to sustain the chain reaction. While the reactor produced less than one watt of power, it demonstrated the feasibility of harnessing nuclear energy, foreshadowing both the development of nuclear power for peaceful uses and the atomic bombs that would later be dropped on Hiroshima and Nagasaki in 1945. This monumental event marked the beginning of a new era in energy production and weaponry, with profound implications for global politics and the future of science.
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First Nuclear Chain Reaction Achieved
First Nuclear Chain Reaction Achieved
On December 2, 1942, the first sustained nuclear chain reaction was achieved at the University of Chicago in Chicago, Illinois, by a team of scientists led by Italian physicist Enrico Fermi. It was a milestone in the history of science, and helped further the development of not only the atomic bomb, but also peaceful pursuits such as nuclear power .
In the 1930s German scientists Otto Hahn and Fritz Strassman first observed the fission of Uranium atoms by neutron bombardment. This led Leo Szilard to theorize that a chain reaction emitting tremendous amounts of energy might be possible to create under artificial conditions. Albert Einstein, whose mathematical theorems on the relationship between mass, light, and energy helped spur interest in nuclear fission to begin with, wrote a letter to President Franklin D. Roosevelt in 1939 requesting funds for further research. Einstein's request was largely ignored until the United States entered World War II. When Roosevelt learned that the Germans were potentially capable of developing their own nuclear device, he approved the Manhattan Project with the goal of producing an atomic bomb.
The top secret Manhattan Project was supervised by General Leslie Grove. Since most of the leading nuclear physicists in the United States were Europeans whose countries were under Axis control, and many were also Jews who as a race were targeted by the Nazis for extermination, they readily agreed to join the venture. Fermi, who developed the first artificial radioactive isotopes, worked with Szilard at the University of Chicago to create the first self-sustained chain reaction. Their reactor or “nuclear pile” was called Chicago Pile Number One (CP-1), and used Uranium-235 embedded in graphite to achieve a controlled reaction based on a steady flow of neutrons to split the U-235 atoms. Each atom thus split generates additional neutrons which split even more atoms, hence the nature of the term chain reaction.
Fermi's nuclear pile produced less than one Watt of power when its chain reaction got underway. Nevertheless, it proved the feasibility of nuclear power and the awesome potential of nuclear weapons ultimately realized in the atomic bombs used to destroy Hiroshima and Nagasaki in 1945 to bring World War II to an end.