Archive | June 2017

Fission Bombs and H-Bombs

Nuclear ComparisonJuly 16th, 1945 at 5:29 am in Alamogordo, New Mexico, the very first atom bomb was denoted. The bomb was called the “Gadget,” and the process of harnessing the power of fission to create such a devastating weapon began as early as 1939, with a budget of only $6,000 for research. At the end of the project $2 billion was invested into it.  And the destructive power of this now mediocre weapon had a yield of 15,000-20,000 tons of TNT. The “Gadget” used plutonium-239 as the fuel source to produce the intense explosion. Just a month later two atom bombs were denoted on Japan. The first atom bomb dropped on Japan, in Hiroshima was named “Little Boy.” It was fueled with two pieces of uranium-235 that weighed 140 lbs. The reason “Little Boy” had two pieces of uranium-235 was to start the nuclear chain reaction. One of the uranium rods would fire into the second by a gun propelling it, resulting in fission chain reaction. Out of that only about 1-2 pounds of the uranium-235 actually fission. Fission happens when neutrons strikes a nucleus of an isotope releasing great amount of energy. The fission process becomes self-sustaining as neutrons constantly get shot from atoms being split. This chain-reaction is what produces an atomic explosion.

August 9th, 1945, the second atomic bomb was dropped on Japan, this time in Nagasaki. The atomic bomb, named “Fat Man,” with a yield of 20 KT. This time, instead of using uranium-235, “Fat Man” was fueled with plutonium-239; 13.63 lbs of it, which is about the size of a softball. Surrounding the plutonium-239 fuel rod is 5, 300 lbs of conventional explosives. The reasoning for this design is that when the conventional explosives go off around the plutonium-239, crushing the plutonium, multiplying the density and pressure into a critical state.  And about only one kilogram of the plutonium actually fission, blowing away the rest of the plutonium-239. This design had to be made because of plutonium’s different nature compared to uranium’s.

The largest fission bomb ever detonated was by the U.S. called Ivy King. Ivy King had a yield of 500 kt and for the material; 60 kg of highly enriched uranium made into a thin-walled sphere equivalent to about four critical masses. This atom bomb is 25 times more destructive than “Fat Man,” but there’s an even more devastating bomb… hydrogen bombs. Hydrogen bombs or, also known as thermonuclear bombs, produce a much higher explosive yield. On July 25, 1950, Harry Truman gave the decision to begin the research and construction of the hydrogen bomb, even though David Lilienthal, chairman of the Atomic Energy Commission, advised against it, because he warned that it will only escalate the cold war. Even after being told of the possible risk, he continued with it. The two main ingredients for this hydrogen bomb are plutonium and tritium. The way a hydrogen bomb works is quite different compared to a fission bomb. A hydrogen bomb uses the energy released when two light atomic nuclei fuse, to form a heavier nuclei. In common conditions atomic nuclei carry positive electrical charges that act to repel other nuclei and inhibit them from getting close to one another. In temperatures of millions of degrees the positively charged nuclei gain sufficient kinetic energy to overcome their mutual electric repulsion and approach close enough to each other to combine under the attraction of the short-range nuclear force. The very light nuclei of hydrogen atoms are perfect applicants for this fusion process because they carry weak positive charges and therefore have less resistance to overcome.

A hydrogen bomb has three stage: the first stage is fission, the second is fusion, and the third is fission again. The first stage is the “trigger,” typically a plutonium bomb is used, and when the energy is released fission first starts and at the center of the plutonium is  tritium, deuterium or lithium deuteride, and this will cause the fusion stage. For the third stage the fusion process causes a unbelievable eruption of very powerful neutrons that they can produce fission atoms of uranium-238 which is not possible at low energy levels. This stage doubles the potency of the bomb, and produces most of the radioactive fallout from the weapon. Typical fission bombs have a limit to their power, but the almighty H-bomb has no limit to its power. The H-bomb can be made as powerful as you, all you need to do is add more deuterium/tritium to the second stage. The H-bomb is not measured in kilotons, its measured in megatons, equivalent to the explosive power of millions of tons of TNT. They are thousands of times as powerful as Ivy King.

October 30, 1961, the largest explosion made by man denoted over the Novaya Zemlya archipelago in northern Russia. This bomb was an H-bomb, made by the Soviets to show-off to the U.S. the name of this bomb is the Tsar Bomba; it had a yield of 50 megatons which is 50000000 of TNT, and the Tsar Bomba was originally planned to have 100 megatons, but the Soviets released that it would have been too dangerous form all the fallout, and the delivery plane would not have adequate time to escape the blast. The bomb itself weighed 59,525 lbs, and was 26 feet in length and 6.9 feet in diameter. The Tsar Bomba yield was about 1,570 times more powerful than the yield of the fission bombs dropped on Hiroshima and Nagasaki combined. And in all of the efforts to build this overkill of a bomb, it had no military purposes. The Tsar Bomba was just too heavy for intercontinental flights, but that was in 1961, so it’s possible that today it can be transported far distances.