This X-ray energy produces the blast and fire which are normally the purpose of a nuclear explosion. Boundless vets and curates high-quality, openly licensed content from around the Internet.
This particular resource used the following sources:. Skip to main content. Nuclear Chemistry. Search for:. The Atomic Bomb. Learning Objective Describe the chemical reaction which fuels an atomic bomb. To detonate the bomb, the explosives were ignited, releasing a shock wave that compressed the inner plutonium and led to its explosion. Browse our collection of oral histories with workers, families, service members, and more about their experiences in the Manhattan Project.
Skip to main content. Science Behind the Atom Bomb. History Page Type:. Thursday, June 5, Fission The isotopes uranium and plutonium were selected by the atomic scientists because they readily undergo fission.
Criticality In order to detonate an atomic weapon, you need a critical mass of fissionable material. The Difference Between the Bombs Little Boy and Fat Man utilized different elements and completely separate methods of construction in order to function as nuclear weapons. Fat Man Powered by plutonium , Fat Man could not use the same gun-type design that allowed Little Boy to explode effectively - the form of plutonium collected from the nuclear reactors at Hanford, WA for the bomb would not allow for this strategy.
Atomic Glossary Atom : building blocks of matter; made up of a small, dense nucleus surrounded by a cloud of electrons negatively-charged particles Nucleus : makes up the center of the atom; consists of a number of positively-charged protons and a neutral no charge neutrons.
An atom is classified by the number of protons and neutrons in its nucleus. The number of protons determines which chemical element the atom is e. The Soviet Union detonated a hydrogen bomb in the megaton range in August The US exploded a 15 megaton hydrogen bomb on 1st March, It had a fireball of 4.
If one of these bombs were ever used, the effect would be catastrophic. The heart of a nuclear explosion reaches a temperature of several million degrees centigrade. Over a wide area the resulting heat flash literally vaporises all human tissue.
People inside buildings or otherwise shielded will be indirectly killed by the blast and heat effects as buildings collapse and all inflammable materials burst into flames. Those in underground shelters who survive the initial heat flash will die as all the oxygen is sucked out of the atmosphere.
This is what happened:. Designers were able to improve the basic implosion-triggered design. In , American physicist Edward Teller invented the concept of boosting. Boosting refers to a process whereby fusion reactions are used to create neutrons, which are then used to induce fission reactions at a higher rate. It took another eight years before the first test confirmed the validity of boosting, but once the proof came, it became a popular design. In the years that followed, almost 90 percent of nuclear bombs built in America used the boost design.
Of course, fusion reactions can be used as the primary source of energy in a nuclear weapon, too. In the next section, we'll look at the inner workings of fusion bombs. Fission bombs worked, but they weren't very efficient. It didn't take scientists long to wonder if the opposite nuclear process -- fusion -- might work better. Fusion occurs when the nuclei of two atoms combine to form a single heavier atom.
At extremely high temperatures, the nuclei of hydrogen isotopes deuterium and tritium can readily fuse, releasing enormous amounts of energy in the process.
Weapons that take advantage of this process are known as fusion bombs , thermonuclear bombs or hydrogen bombs. Fusion bombs have higher kiloton yields and greater efficiencies than fission bombs, but they present some problems that must be solved:. Scientists overcome the first problem by using lithium-deuterate, a solid compound that doesn't undergo radioactive decay at normal temperature, as the principal thermonuclear material.
To overcome the tritium problem, bomb designers rely on a fission reaction to produce tritium from lithium. The fission reaction also solves the final problem. The majority of radiation given off in a fission reaction is X-rays , and these X-rays provide the high temperatures and pressures necessary to initiate fusion. So, a fusion bomb has a two-stage design -- a primary fission or boosted-fission component and a secondary fusion component.
To understand this bomb design, imagine that within a bomb casing you have an implosion fission bomb and a cylinder casing of uranium tamper. Within the tamper is the lithium deuteride fuel and a hollow rod of plutonium in the center of the cylinder. Separating the cylinder from the implosion bomb is a shield of uranium and plastic foam that fills the remaining spaces in the bomb casing.
Detonation of the bomb causes the following sequence of events:. All of these events happen in about billionths of a second billionths of a second for the fission bomb implosion, 50 billionths of a second for the fusion events. The result is an immense explosion with a 10,kiloton yield -- times more powerful than the Little Boy explosion.
It's one thing to build a nuclear bomb. It's another thing entirely to deliver the weapon to its intended target and detonate it successfully.
This was especially true of the first bombs built by scientists at the end of World War II. Writing in a issue of Scientific American, Philip Morrison, a member of the Manhattan Project , said this about the early weapons: "All three bombs of -- the [Trinity] test bomb and the two bombs dropped on Japan -- were more nearly improvised pieces of complex laboratory equipment than they were reliable weaponry.
The delivery of those bombs to their final destination was improvised almost as much as their design and construction. The components of the Fat Man bomb, carried by three modified Bs, arrived on August 2. A team of 60 scientists flew from Los Alamos, N.
The Little Boy bomb -- weighing 9, pounds 4, kilograms and measuring 10 feet 3 meters from nose to tail -- was ready first. Paul Tibbets. The plane made the mile 1,kilometer trip to Japan and dropped the bomb into the air above Hiroshima, where it detonated at exactly a. On August 9, the nearly 11,pound 5,kilogram Fat Man bomb made the same journey aboard the Bockscar, a second B piloted by Maj.
Charles Sweeney. Its deadly payload exploded over Nagasaki just before noon. Today, the method used in Japan -- gravity bombs carried by aircraft -- remains a viable way to deliver nuclear weapons. But over the years, as warheads have decreased in size, other options have become available. Many countries have stockpiled a number of ballistic and cruise missiles armed with nuclear devices. Most ballistic missiles are launched from land-based silos or submarines.
They exit the Earth's atmosphere, travel thousands of miles to their targets and re-enter the atmosphere to deploy their weapons. Cruise missiles have shorter ranges and smaller warheads than ballistic missiles, but they are harder to detect and intercept. They can be launched from the air, from mobile launchers on the ground and from naval ships.
Designed to target smaller areas, TNWs include short-range missiles, artillery shells, land mines and depth charges. Portable TNWs, such as the Davy Crockett rifle, make it possible for small one- or two-man teams to deliver a nuclear strike. The detonation of a nuclear weapon unleashes tremendous destruction, but the ruins would contain microscopic evidence of where the bombs' materials came from.
The detonation of a nuclear bomb over a target such as a populated city causes immense damage. The degree of damage depends upon the distance from the center of the bomb blast, which is called the hypocenter or ground zero. The closer you are to the hypocenter, the more severe the damage. The damage is caused by several things:. At the hypocenter, everything is immediately vaporized by the high temperature up to million degrees Fahrenheit or million degrees Celsius. Outward from the hypocenter, most casualties are caused by burns from the heat, injuries from the flying debris of buildings collapsed by the shock wave and acute exposure to the high radiation.
Beyond the immediate blast area, casualties are caused from the heat, the radiation and the fires spawned from the heat wave. In the long term, radioactive fallout occurs over a wider area because of prevailing winds.
The radioactive fallout particles enter the water supply and are inhaled and ingested by people at a distance from the blast. Scientists have studied survivors of the Hiroshima and Nagasaki bombings to understand the short-term and long-term effects of nuclear explosions on human health. Radiation and radioactive fallout affect those cells in the body that actively divide hair, intestine, bone marrow, reproductive organs. Some of the resulting health conditions include:.
These conditions often increase the risk of leukemia, cancer , infertility and birth defects.
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