In 1938, the Italian physicist Enrico Ferme, who fled to New York to escape fascism, Discover Where this type occurred: uranium. For fear that the Nazis will also discover the ability of this element to produce a series of reaction, Manhattan Project Born in 1940, a secret program for the development of nuclear weapons led by Arthur Compton. Compton has formed a research group, also included Fermi and Szilaard, which will continue to conduct experiments on nuclear chain reactions. Theoretical physicist Julius Robert Obenheimer was also part of the team.
On December 2, 1942, the first actual experience was conducted under the Football field at the University of Chicago; In the Squash Court, the physicists built a reactor called it “Chicago Pack 1” This has achieved the first continuous nuclear reaction by humans, providing confirmation of the idea of Szillard. In 1943, Obenheimer became a project manager at Los Alamos laboratories in New Mexico, where the first real nuclear device in history will be designed. On July 16, 1945, the United States detonated it in the New Mexico Desert. Twenty days later, on August 6, a similar bomb fell on the Japanese city of Hiroshima, and on August 9 in Nagasaki, which led to Japan surrendering after several days and the end of World War II.
The issue of Nawa
As we all learn in school, the atoms consist of a nucleus of neutrons and protons, around which electrons revolve. Atomic cores can unite to form larger atoms, or fragment to form smaller atoms. The first case in nuclear fusion is called the process that occurs in the stars, which researchers today are trying to re -create in the laboratory as a means of energy production. Under heat and infernal pressure, atoms merge together to form heavier atoms. For example, in a star like the sun, the hydrogen nuclei is flexible to form a helium nuclei. This process launches energy, which radiates the solar system, creating conditions that are suitable for living on Earth.
However, when the nucleus is divided, we call it nuclear fission, which we exploit in a controlled manner in nuclear power plants in an unintentional manner in nuclear bombs. In this case, unstable heavy atoms are divided into lighter atoms, a process that also releases energy. In addition to energy, excess neutrons are also released, which specifically leads to the reaction of the fission chain imagined by Szilaard. However, the superior material must reach importance – a condition where enough neutrons are launched and strike other atoms to continue to run more atoms for division. In a nuclear reactor, achieving importance is the goal; In an atomic bomb, it must be crossed, as one reaction leads to multiple reactions and causes the process to escalate.
From fission to fusion
Those weapons discussed so far are “classic” offspring, based on fission. An atomic bomb is usually operated by a chemical explosion, which presses a mass of uranium or plutonium until it exceeds importance. Subsequent developments in this field of research, however, led to another type of nuclear devices, called a fusion bomb. These heat nuclear bombs are called a sequence of two explosions. The main explosion is equivalent to the fission bomb, with the above -mentioned sequence of the chemical explosion and the fission chain. The energy released by the main explosion then leads to a secondary explosion, and is used to cause hydrogen atoms. The most powerful and tested device is the famous Caesar bomb, which was detonated in the Arctic in 1961 by the Soviet Union.
How the explosion occurs
We all have a mushroom cloud image in our minds. But how does it arise? Once an atomic bomb exploded, within the first second, there is a sudden energy launch in the form of free neutrons and gamma. The explosion appears as a fiery field that expands to dozens of kilometers from the trigger point. This fiery explosion, which rises to the air, creates the shape of the typical mushroom. Thermal flash occurs. The heat emitted from fires can start and cause burns even a kilometer from the center of the explosion (depending on the strength of the bomb).
Expanding very quickly, the explosion creates a shock wave, a sudden change in atmospheric pressure that creates a lot of destruction associated with atomic bombs. However, the peculiarity of atomic bombs are radioactive repercussions: a shower of fission that spreads in the area surrounding the explosion, which can be contaminated with radioactive elements for decades.
This story was originally appeared on Wireless Italy It was translated from Italian.
https://media.wired.com/photos/6891e09ed3490a9be78e30b5/191:100/w_1280,c_limit/615303584
Source link