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The History of Hydrogen Bomb and Why it Should be Banned
By John Richard Shanebrook AuthorHouse
Copyright © 2016 John Richard Shanebrook
All rights reserved.
ISBN: 978-1-5049-8484-3
CHAPTER 1
Atom Bombs, Nuclear Radiation, and Photons
Atom bombs provide the triggers for hydrogen bombs by emitting nuclear radiation, heat energy, and photons.
Atom bombs work by using chemical explosives to compress a small ball of plutonium into a much smaller supercritical state, in which a nuclear chain reaction occurs. This process of violent and rapid compression, called implosion, was used to detonate the plutonium atom bomb over Nagasaki, Japan, on August 9, 1945. A key element in the design of atom bombs is the neutron generator, which releases millions of neutrons at the start of the nuclear chain reaction.
The Nagasaki bomb employed a grape-sized device located at the center of the plutonium sphere. Designed by Hans Bethe, it was called "Urchin" and was highly compressed during the implosion process. This caused a beryllium and polonium reaction that released millions of neutrons that flowed radially outward into the plutonium-239 sphere. A nuclear chain reaction then commenced that, in less than one millionth of a second, generated sufficient heat energy to blow the entire bomb apart with an explosive yield equivalent to twenty thousand tons of TNT. In this book, this will be written as 20 kt (TNT), where kt denotes kilotons. Later, the explosive yield of hydrogen bombs will be written in millions of tons of TNT; that is, expressed in Mt (TNT), where Mt denotes megatons.
After Nuclear War I ended in August 1945, the United States continued work on nuclear weapons at Los Alamos, New Mexico. Much of this work focused on improving the efficiency of atom bombs by increasing the number of plutonium fissions during the explosion process. This work proved to be very successful in producing much smaller atom bombs without sacrificing yield. One innovation was to employ two different neutron generators for the atom bomb triggers used to ignite hydrogen bombs. One neutron generator was external to the bomb, and the other was internal and located, like Urchin, at the center of the plutonium sphere.
The external device fired a stream of neutrons directly at the plutonium sphere. The new Urchin used a deuterium-tritium thermonuclear reaction to release lots of neutrons that "boosted" the yield of the atomic trigger. This technique of boosting the yield of atom bombs will be discussed in a later chapter. It is noted that the external device is designated NG in Figure 4.
Nuclear Radiation
At the very instant of denotation of the atom bomb's trigger, nuclear radiation pours out of the region of plutonium fission. Much of this radiation is in the form of gamma rays that move at the speed of light. This stream of radiation is extremely powerful and originates from nuclear processes. It is noted that X-rays are also emitted, but the gamma rays are much more energetic. Both gamma rays and X-rays are forms of electromagnetic radiation, characterized by waves that propagate through space with a certain frequency and wavelength. Gamma rays have a shorter wavelength than X-rays, and their energies are measured in hundreds of thousands of electron volts.
The concept of an electron volt is a convenient way to express the energy levels of all electromagnetic radiation. One electron volt is the amount of kinetic energy that an electron gains when it is accelerated through a potential difference of one volt.
It is noted that gamma rays were first discovered by Paul Villard while he was working in Paris in 1900. Uranium was observed to decay by emitting an alpha particle (helium nucleus), and further decay involved the emission of gamma rays. In this way, radioactive elements transform into other elements. The emission of gamma rays reduces the energy level of the nucleus.
Gamma rays are also common in astrophysical processes such as those in the stars. Our sun burns hydrogen by thermonuclear fusion, and it emits gamma rays during this process. In fact, outer space is full of this form of nuclear radiation from stellar processes, including supernova explosions. Astronauts must be shielded from this radiation by spacecraft designed to protect human occupants. Likewise, humans on spaceship Earth are protected from gamma rays and all cosmic rays by Earth's atmosphere and its ozone layer.
Finally, gamma rays can pass through matter but lose energy when they do so. For example, when gamma rays intersect electrons, they can energize them to the point where they leave their orbits. In this case, the affected atom is now positively charged and is called an ion. This process of dislodging electrons is called ionization, and the resulting charged nuclei can have deleterious effects on human cells, including possible cancerous growths and mutagenic changes to human DNA. Conversely, gamma rays can be used to destroy cancerous tumors inside the human body. Radiologists routinely use cobalt-60 to focus its gamma rays on cancer cells.
Photons
For the purposes of this book, it is convenient to also view electromagnetic radiation as tiny particles (packets) of energy called photons. Thus, gamma rays and X-rays can be viewed as both waves and particles in motion. This duality was first explained by the French physicist Louis de Broglie in 1924. This was a major breakthrough in the study of light energy, which originally had been viewed as waves of energy.
By viewing light as particles of energy, also called quanta, it was possible to establish a whole new theory of physics called quantum mechanics. One example of this duality that has proved useful is the concept of an electron. Sometimes it is convenient to view electrons as particles that orbit a nucleus. Other times it is convenient to view electrons as waves of energy around a nucleus. In this case, an atom is viewed as a nucleus surrounded by electron clouds. These clouds have different energy levels that depend on their position relative to the nucleus.
The modern view of light energy is to view light quanta as photons that move through space at the speed of light. These packets of pure energy are massless but form the rays of light from the sun. These sunbeams reach Earth and are instrumental in all life processes, including photosynthesis.
It is remarkable that photons exert forces on objects when they intersect them. A good analogy is the force of the wind on objects such as wind machines. These aerodynamic forces on the blades of a wind machine cause the blades to rotate and power an electric generator.
The flow of photons (and subatomic particles) from the sun forms the so-called solar wind, which intersects Earth. One result of this interaction is a shock wave that forms around Earth and its magnetic field. This shock wave is a sudden interruption in the flow of the solar wind. This wind contains photons and electrically charged protons and electrons. The latter spin around the magnetic field lines near the North and South Poles. This interaction produces a glow called the aurora borealis (northern lights) and aurora australis (southern lights).
In outer space, the solar wind can be used to propel space vehicles via solar sails. These sails consist of thin, lightweight material that has a large surface area to catch the solar wind. When photons hit these sheets, they impart momentum to the vehicle and push it forward, away from the sun. These photon-generated forces are relatively small, but over time, very high speeds are possible, up to a significant fraction of the speed of light.
Similarly, photons, when properly directed, can cause compression of a cylindrical object when they push radially inward around the entire external surface area of the cylinder. This is exactly what happens in a hydrogen bomb when super-high-energy photons are generated (in the form of gamma rays) by an exploding atom bomb. These photons are focused onto the periphery of a cylinder of fusion fuel (hydrogen isotopes). The result is an enormous compression of the cylinder into a much smaller volume, with a concomitant increase in temperature to thermonuclear levels like those on the sun.
Fusion then ensues, with release of energy in the form of light, heat, and radiation. The latter includes neutrons that can be used to fission uranium in the external casing of the bomb. All of this happens in less than a millionth of a second before the whole bomb assembly blows apart.
This explosion process started with fission inside the atom bomb trigger, proceeded to fusion inside the cylinder of fusion fuel, and ended with fission of the uranium bomb casing. Hence, this weapon is called a fission-fusion-fission weapon. Refer to Figure 4, where the bomb casing is made of uranium-238.
CHAPTER 2
Four Years of Atom Bomb Monopoly
From 1945 to 1949, the United States had a monopoly on nuclear weapons until the USSR exploded its first nuclear device on August 29, 1949.
After World War II and Nuclear War I, many scientists who had worked on the atom bombs that devastated Hiroshima and Nagasaki were depressed and unhappy. These included their leader at Los Alamos, J. Robert Oppenheimer, who was plagued by guilt. He later forcefully opposed the American program to build hydrogen bombs. He was eventually severely punished for this opposition by a public trial that resulted in the removal of his security clearance. Oppenheimer never recovered from this public humiliation. He then left public life and retreated to Princeton, New Jersey, where he directed the Institute for Advanced Study. Ironically, Albert Einstein was also there and at least symbolically, Oppenheimer was his boss.
After Nuclear War I, work at Los Alamos continued on the development of better and more efficient atom bombs (using uranium and/or plutonium). Part of this program was to test new designs at Bikini Atoll in the Pacific Ocean (Marshall Islands), beginning in the summer of 1946. Code-named "Operation Crossroads," this test series consisted of two nuclear tests, with the most notable one being an underwater explosion on July 24,1946. Called the Baker test, it had an explosive yield of some 21,000 tons of TNT (equivalent).
The purpose of the Baker test was to see the effects of an underwater atom bomb explosion on a fleet of naval vessels anchored nearby. The blast came from a moored container some twenty-seven meters below the surface of the water.
Many observers were present for this test, and photographic film results became well known around the world, due to the spectacular gushing column of water that was exploded upward. The results of this 21 kt nuclear explosion were devastating for several reasons. Eight ships were sunk, and some ninety others were severely contaminated by the radioactive fallout from the subsequent rain that drenched the target fleet.
Some ships located a few miles from the blast received radioactive doses of 1,000 rems to 5,000 rems. Due to this high radioactivity, several ships were scuttled on-site. This apparent act of desperation later became accepted practice by other nations as a way to get rid of nuclear waste by ocean dumping.
The Baker test also revealed some astonishing biological results.
These came from a study of the radioactivity in the Bikini lagoon by the US Navy, using Geiger counters and a small boat that cruised through the contaminated waters. It was found that the bottom of this boat became radioactive from green slime that formed on the bottom of the boat. Further examination showed that certain algae in the slime had a great propensity to attract and concentrate certain fission products. The level of concentration can be extremely high. For example, some ocean organisms can concentrate certain radioactive fission fragments by a factor of some 100,000 times that found in their local environment. The Baker test also had serious political fallout. Shortly after Nuclear War I, the United States developed a plan for international control of nuclear weapons and peaceful applications of nuclear energy. The report describing this plan was largely written by J. Robert Oppenheimer, as part of a committee headed by David Lilienthal. In March 1946, US Secretary of State Dean Acheson released this report, and it subsequently became known as the Acheson-Lilienthal Report.
Shortly thereafter, Bernard Baruch presented this plan to the United Nations for possible adoption. Here it was known as the Baruch Plan. It is noted that a better name for this plan, and a less confusing one, should have been the Oppenheimer Plan. After all, he was known as the "father of the atom bomb," and he was now issuing a clarion call for international control of all nuclear weapons.
The Baruch Plan proposed the formation of an Atomic Development Authority, which would oversee all aspects of nuclear energy from cradle to grave. The latter would include the daunting task of safe storage of nuclear waste for thousands of years. The former would include the mining of uranium and the manufacture of fuel rods for nuclear reactors. Key to success of this plan would be frequent and strict inspection of all nuclear facilities involved in the production of nuclear explosives and peaceful applications. It is noted that the USSR, at that time, was an extremely secretive society where any inspections by foreign entities would be frowned upon, to say the least.
The Baruch Plan proposal to the United Nations specifically pointed to the horrible dangers of nuclear weapons if used in massive surprise attacks. That is, any nation that was subjected to a nuclear Pearl Harbor-type of attack was in danger of near total destruction. It was obvious that international controls to prevent such nuclear attacks were paramount to the security and survival of all nations. Even the survival of humanity itself was at risk, per the remarks of Emperor Hirohito during his radio broadcast on the surrender of Japan in August 1945.
Alas, the USSR did not go along with the provisions of the Baruch Plan and rejected it. They felt there was little to be gained from the Baruch Plan, and they were very wary of US intentions as regards to nuclear weapons.
One reason for the Soviet rejection of the Baruch Plan was the failure of the United States to share its nuclear accomplishments from the Manhattan Project with the USSR. That is, the United States and the United Kingdom worked closely together to develop nuclear weapons during World War II. The USSR was an ally of both the United States and the United Kingdom during World War II, yet was not invited to participate in the Manhattan Project. American secrecy prevailed, and the USSR was never invited to share in the tremendous technological accomplishments that led to the devastation of Hiroshima and Nagasaki in Nuclear War I. Joseph Stalin was shocked and probably dismayed when he learned of these atom bomb attacks.
To counter US secrecy, the USSR developed a network of spies that infiltrated the US super-secret Manhattan Project. Two of these spies were Klaus Fuchs and David Greenglass. Both worked at Los Alamos, New Mexico, on the atom bombs used in Nuclear War I to devastate Hiroshima and Nagasaki. They transmitted extremely important designs and construction details on US atom bombs to the USSR.
It is noted that Klaus Fuchs was a brilliant master spy who worked on atom bombs and early designs of hydrogen bombs at Los Alamos from 1944 to 1946. This work included the following:
1) Fuchs played a key role in the design and testing of the initiator for plutonium implosion atom bombs. He was awarded a patent (with R. Sherr) that used a cone configuration to focus a shock wave into a penetrating jet. The flow from the jet was used to break open a barrier between polonium-210 and beryllium. The resulting mixing produced billions of neutrons that helped to fission the plutonium at the center of the bomb.
2) Fuchs also received a patent, with John von Neumann (on May 28, 1946), for a scheme to ignite hydrogen bombs. This document also included a description of Edward Teller's design for a hydrogen bomb called the "Classical Super." It is noted that this design was very crude and was eventually discarded as unworkable. The main problem was failure to ignite and continue to burn the fusion fuel (deuterium).
The Teller Super design relied on exploding an atom bomb to produce the high temperatures needed to fuse together the nuclei of deuterium. The basic idea was to ignite this fusion fuel and keep it burning (like a candle) until all the fuel was exhausted. Teller liked this idea because it magnified the yield of the atom bomb used by a factor of about a thousand times. Moreover, there was theoretically no limit to the yield of this type of hydrogen bomb. That is, the size of the explosion would be limited only by the amount of fusion fuel stored inside the bomb casing. On the other hand, fission atom bombs are limited in yield to about 500 kt due to the need for a nuclear chain reaction to keep the fission chain reaction going. Thermonuclear fusion reactions proceed by burning fusion fuel, without any need for a chain reaction.
1) Fuchs also attended a top-secret meeting at Los Alamos on April 18-20, 1946. The purpose of this conference was to review US progress on hydrogen bombs and to outline future work. In preparation for this meeting, Edward Teller and his colleagues prepared a fifty-nine-page report on thermonuclear fusion weapons. This report was dated April 15, 1946, and included a review of the physics of the Teller Super design. It was recommended that the United States begin a large-scale effort to develop hydrogen bombs. This included a recommendation to develop facilities for the production of tritium. It is noted that these recommendations were largely ignored (at that time) and angered Teller so much that he quit working on hydrogen bombs at Los Alamos and returned to academia at the University of Chicago (September 17, 1951).
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Excerpted from The History of Hydrogen Bomb and Why it Should be Banned by John Richard Shanebrook. Copyright © 2016 John Richard Shanebrook. Excerpted by permission of AuthorHouse.
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