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Inertial Confinement Fusion
Inertial confinement fusion (ICF) is a fusion energy process that initiates nuclear fusion reactions by compressing and heating targets filled with fuel. The targets are small pellets, typically containing deuterium (2H) and tritium (3H). Typically, short pulse lasers deposit energy on a hohlraum. Its inner surface vaporizes, releasing X-rays. These converge on the pellet's exterior, turning it into a plasma. This produces a reaction force in the form of shock waves that travel through the target. The waves compress and heat it. Sufficiently powerful shock waves achieve the Lawson criterion for fusion of the fuel. ICF is one of two major branches of fusion research; the other is magnetic confinement fusion (MCF). When first proposed in the early 1970s, ICF appeared to be a practical approach to power production and the field flourished. Experiments demonstrated that the efficiency of these devices was much lower than expected. Throughout the 1980s and '90s, experiments were co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lawson Criterion
The Lawson criterion is a figure of merit used in nuclear fusion research. It compares the rate of energy being generated by fusion reactions within the fusion fuel to the rate of energy losses to the environment. When the rate of production is higher than the rate of loss, the system will produce net energy. If enough of that energy is captured by the fuel, the system will become self-sustaining and is said to be ignited. The concept was first developed by John D. Lawson in a classified 1955 paper that was declassified and published in 1957. As originally formulated, the Lawson criterion gives a minimum required value for the product of the plasma (electron) density ''n''e and the "energy confinement time" \tau_E that leads to net energy output. Later analysis suggested that a more useful figure of merit is the triple product of density, confinement time, and plasma temperature ''T''. The triple product also has a minimum required value, and the name "Lawson criterion" may re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen
Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter. Under standard conditions, hydrogen is a gas of diatomic molecules with the chemical formula, formula , called dihydrogen, or sometimes hydrogen gas, molecular hydrogen, or simply hydrogen. Dihydrogen is colorless, odorless, non-toxic, and highly combustible. Stars, including the Sun, mainly consist of hydrogen in a plasma state, while on Earth, hydrogen is found as the gas (dihydrogen) and in molecular forms, such as in water and organic compounds. The most common isotope of hydrogen (H) consists of one proton, one electron, and no neutrons. Hydrogen gas was first produced artificially in the 17th century by the reaction of acids with metals. Henry Cavendish, in 1766–1781, identified hydrogen gas as a distinct substance and discovere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coulomb Barrier
The Coulomb barrier, named after Coulomb's law, which is in turn named after physicist Charles-Augustin de Coulomb, is the energy barrier due to electrostatic interaction that two nuclei need to overcome so they can get close enough to undergo a nuclear reaction. Potential energy barrier This energy barrier is given by the electric potential energy: :U_\text = where :''ε''0 is the permittivity of free space; :''q''1, ''q''2 are the charges of the interacting particles; :''r'' is the interaction radius. A positive value of ''U'' is due to a repulsive force, so interacting particles are at higher energy levels as they get closer. A negative potential energy indicates a bound state (due to an attractive force). The Coulomb barrier increases with the atomic numbers (i.e. the number of protons) of the colliding nuclei: :U_\text = where ''e'' is the elementary charge, and ''Zi'' the corresponding atomic numbers. To overcome this barrier, nuclei have to collide at high velocities, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kinetic Energy
In physics, the kinetic energy of an object is the form of energy that it possesses due to its motion. In classical mechanics, the kinetic energy of a non-rotating object of mass ''m'' traveling at a speed ''v'' is \fracmv^2.Resnick, Robert and Halliday, David (1960) ''Physics'', Section 7-5, Wiley International Edition The kinetic energy of an object is equal to the work, or force ( F) in the direction of motion times its displacement ( s), needed to accelerate the object from rest to its given speed. The same amount of work is done by the object when decelerating from its current speed to a state of rest. The SI unit of energy is the joule, while the English unit of energy is the foot-pound. In relativistic mechanics, \fracmv^2 is a good approximation of kinetic energy only when ''v'' is much less than the speed of light. History and etymology The adjective ''kinetic'' has its roots in the Greek word κίνησις ''kinesis'', meaning "motion". The dichoto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrostatic Force
Coulomb's inverse-square law, or simply Coulomb's law, is an experimental law of physics that calculates the amount of force between two electrically charged particles at rest. This electric force is conventionally called the ''electrostatic force'' or Coulomb force. Although the law was known earlier, it was first published in 1785 by French physicist Charles-Augustin de Coulomb. Coulomb's law was essential to the development of the theory of electromagnetism and maybe even its starting point, as it allowed meaningful discussions of the amount of electric charge in a particle. The law states that the magnitude, or absolute value, of the attractive or repulsive electrostatic force between two point charges is directly proportional to the product of the magnitudes of their charges and inversely proportional to the square of the distance between them. Coulomb discovered that bodies with like electrical charges repel: Coulomb also showed that oppositely charged bodies attract ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Force
The nuclear force (or nucleon–nucleon interaction, residual strong force, or, historically, strong nuclear force) is a force that acts between hadrons, most commonly observed between protons and neutrons of atoms. Neutrons and protons, both nucleons, are affected by the nuclear force almost identically. Since protons have charge +1 ''e'', they experience an electric force that tends to push them apart, but at short range the attractive nuclear force is strong enough to overcome the electrostatic force. The nuclear force binds nucleons into atomic nuclei. The nuclear force is powerfully attractive between nucleons at distances of about 0.8 femtometre (fm, or ), but it rapidly decreases to insignificance at distances beyond about 2.5 fm. At distances less than 0.7 fm, the nuclear force becomes repulsive. This repulsion is responsible for the size of nuclei, since nucleons can come no closer than the force allows. (The size of an atom, of size in the orde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fusion Energy Gain Factor
A fusion energy gain factor, usually expressed with the symbol ''Q'', is the ratio of fusion power produced in a nuclear fusion reactor to the power required to maintain the plasma in steady state. The condition of ''Q'' = 1, when the power being released by the fusion reactions is equal to the required heating power, is referred to as breakeven, or in some sources, scientific breakeven. The energy given off by the fusion reactions may be captured within the fuel, leading to ''self-heating''. Most fusion reactions release at least some of their energy in a form that cannot be captured within the plasma, so a system at ''Q'' = 1 will cool without external heating. With typical fuels, self-heating in fusion reactors is not expected to match the external sources until at least ''Q'' ≈ 5. If ''Q'' increases past this point, increasing self-heating eventually removes the need for external heating. At this point the reaction becomes self-sustaining, a c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lawrence Livermore National Laboratory
Lawrence Livermore National Laboratory (LLNL) is a Federally funded research and development centers, federally funded research and development center in Livermore, California, United States. Originally established in 1952, the laboratory now is sponsored by the United States Department of Energy and administered privately by Lawrence Livermore National Security, LLC. The lab was originally established as the University of California Radiation Laboratory, Livermore Branch in 1952 in response to the detonation of the Soviet Union's first atomic bomb during the Cold War. It later became autonomous in 1971 and was designated a national laboratory in 1981. Lawrence Livermore Lab is primarily funded by the United States Department of Energy, U.S. Department of Energy and it is managed Privately held company, privately and operated by Lawrence Livermore National Security, LLC (a Public-private partnerships in the United States, partnership of the University of California, Bechtel, BW ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stockpile Stewardship
Stockpile stewardship refers to the United States program of reliability testing, viability, and the maintenance of its nuclear weapons without the use of nuclear testing. Because no new nuclear weapons have been developed by the United States since 1992, even its youngest weapons are at least years old (as of ). Aging weapons can fail or act unpredictably in a number of ways: the high explosives that compress their fissile material can chemically degrade, their electronic components can suffer from decay, their radioactive plutonium/uranium cores are potentially unreliable, and the isotopes used by thermonuclear weapons may be chemically unstable as well. Since the United States has also not tested nuclear weapons since 1992, this leaves the task of its stockpile maintenance resting on the use of simulations (using non-nuclear explosives tests and supercomputers, among other methods) and applications of scientific knowledge about physics and chemistry to the specific problems of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear State
Nine sovereign states are generally understood to possess nuclear weapons, though only eight formally acknowledge possessing them. Five are considered to be nuclear-weapon states (NWS) under the terms of the Treaty on the Non-Proliferation of Nuclear Weapons (NPT). In order of acquisition of nuclear weapons, these are the United States, Russia (the successor of the former Soviet Union), the United Kingdom, France, and China. Other states that have declared nuclear weapons possession are India, Pakistan, and North Korea. Since the NPT entered into force in 1970, these three states were not parties to the Treaty and have conducted overt nuclear tests. North Korea had been a party to the NPT but withdrew in 2003. Israel is also generally understood to have nuclear weapons, but does not acknowledge it, maintaining a policy of deliberate ambiguity. Israel is estimated to possess somewhere between 90 and 300 nuclear warheads. One possible motivation for ''nuclear ambiguity'' i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermonuclear Weapon
A thermonuclear weapon, fusion weapon or hydrogen bomb (H-bomb) is a second-generation nuclear weapon design. Its greater sophistication affords it vastly greater destructive power than first-generation nuclear bombs, a more compact size, a lower mass, or a combination of these benefits. Characteristics of nuclear fusion reactions make possible the use of non-fissile depleted uranium as the weapon's main fuel, thus allowing more efficient use of scarce fissile material. Its multi-stage design is distinct from the usage of fusion in simpler Boosted fission weapon, boosted fission weapons. The first full-scale thermonuclear test (Ivy Mike) was carried out by the United States in 1952, and the concept has since been employed by at least the five recognized List of states with nuclear weapons#Recognized nuclear-weapon states, nuclear-weapon states and United Nations Security Council, UNSC Permanent members of the United Nations Security Council, permanent members: the Nuclear weapons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
