27 Sentences With "thermonuclear reaction"

That hydrogen builds up around the white dwarf, and eventually it gets so hot that it erupts in an extremely bright thermonuclear reaction.

A classical nova occurs when a white dwarf star gains matter from its secondary star over a period of time, causing a thermonuclear reaction on the surface that eventually erupts in a single visible outburst.

In 1942, it occurred to Edward Teller, one of the Manhattan scientists, that a nuclear explosion would create a temperature unprecedented in Earth's history, producing conditions similar to those in the center of the sun, and that this could conceivably trigger a self-sustaining thermonuclear reaction in the surrounding air or water.

One of the many projects of JINA-CEE is the maintenance of an up-to-date nuclear reaction rate library called REACLIB. REACLIB contains over 75,000 thermonuclear reaction rates.

The design of Grapple Y was notably successful because much of its yield came from its thermonuclear reaction instead of fission of a heavy uranium-238 tamper, making it a true hydrogen bomb, and because its yield had been closely predicted—indicating that its designers understood what they were doing.

Very high energy-density chemicals such as ballotechnics and others have also been suggested as a means of triggering a pure fusion weapon. Nuclear isomers have also been investigated for use in pure fusion weaponry. Hafnium and tantalum isomers can be induced to emit very strong gamma radiation. Gamma emission from these isomers may have enough energy to start a thermonuclear reaction, without requiring any fissile material.

Jeremy Bernstein, "John von Neumann and Klaus Fuchs: an Unlikely Collaboration", Physics in Perspective 12, no. 1 (March 2010), 36-50. In 1951, Stanislaw Ulam had the idea to use hydrodynamic shock of a fission weapon to compress more fissionable material to incredible densities in order to make megaton-range, two-stage fission bombs. He then realized that this approach might be useful for starting a thermonuclear reaction.

On 16 February 1951, Richter claimed he had successfully demonstrated fusion. He re-ran the experiment for members of the CNEA, later claiming that they had witnessed the world's first thermonuclear reaction. On 23 February, a technician working for the project expressed his concerns about the claims, suggesting that the measurement was likely due to the accidental tilting of the spectrograph's photographic plate while the experimental run was being set up. Richter refused to re-run the experiment.

Ivy King was the largest pure-fission nuclear bomb ever tested by the United States. The bomb was tested during the Truman administration as part of Operation Ivy. This series of tests involved the development of very powerful nuclear weapons in response to the nuclear weapons program of the Soviet Union. The production of Ivy King was hurried to be ready in case its sister project, Ivy Mike, failed in its attempt to achieve a thermonuclear reaction.

The Kremlin's Nuclear Sword: The Rise and Fall of Russia's Strategic Nuclear Forces 1945–2000. Smithsonian Books. . Adding a shell of natural, unenriched uranium around the deuterium would increase the deuterium concentration at the uranium-deuterium boundary and the overall yield of the device, because the natural uranium would capture neutrons and itself fission as part of the thermonuclear reaction. This idea of a layered fission-fusion-fission bomb led Sakharov to call it the sloika, or layered cake.

The committee analyzed Richter's work and concluded that the actual temperature reached in his experiments was far too low to produce a true thermonuclear reaction. They reported their findings to Perón in September 1952; soon after that project was terminated. After the termination of the project, Richter appears to have spent periods of time abroad, including some time in Libya. Eventually he returned to Argentina, where he died in 1991; a short announcement of his death appeared in an obituary published by Microsemanario.

It is well established that Jovian-class planets consist mostly of hydrogen and helium. It is theorised that concentrations of hydrogen and helium isotopes at certain depths of a gas-giant planet may be sufficient to support a fusion chain reaction, if sufficient energy can be delivered to ignite the reaction. If a gas giant has a layer with a large concentration of deuterium (>0.3%), ultra-high-speed ( collision of a sufficiently large asteroid (diameter > ) could ignite a thermonuclear reaction.

Adding two hydrogens to the nitrogen creates oxygen. The oxygen combines with another hydrogen to create helium and carbon, and in the process releases energy. Dr. Research then mentions combining two hydrogen atoms directly into a helium atom in the proton-proton process. Dr. Research continues, telling how science believes the Sun started as a loose cloud of hydrogen gas compressed by gravity and this compression raised the temperature until it reached 30 million degrees and started the thermonuclear reaction.

These can add considerable energy to the reaction; in a typical design as much as 50% of the total energy comes from fission events in the casing. For this reason, these weapons are technically known as fission-fusion-fission designs. In a neutron bomb, the casing material is selected either to be transparent to neutrons or to actively enhance their production. The burst of neutrons created in the thermonuclear reaction is then free to escape the bomb, outpacing the physical explosion.

Further, the energy output was much lower than a typical supernova and the luminosity dropped at a dramatic pace. A team consisting of Poznanski, Joshua Bloom, Alex Filippenko and others concluded that it was a new category of exploding star. This system is believed to consist of a binary pair of white dwarf stars, with helium being transferred from one dwarf to the other. The accreted helium exploded in a thermonuclear reaction on the surface of the more massive white dwarf, resulting in the observed outburst.

Since it is simpler to convert the energy of charged particles into electrical power than it is to convert energy from uncharged particles, an aneutronic reaction would be attractive for power systems. Some proponents see a potential for dramatic cost reductions by converting energy directly to electricity, as well as in eliminating the radiation from neutrons, which are difficult to shield against.Larry T. Cox Jr., Franklin B. Mead Jr. and Chan K. Choi Jr., (1990). "Thermonuclear Reaction Listing with Cross-Section Data for Four Advanced Reactions"], Fusion Technology, Volume 18, no. 2.

In these documents the classical super was described as consisting of a gun-type Uranium-235 primary with beryllium oxide tamper and a secondary consisting of a long cylinder with deuterium, doped with tritium near the primary. The design of the RDS-6t was similar to this classical super. The difference was that the light shell of beryllium oxide was replaced by a heavy shell. The assumption was that the deuterium tritium mixture could be easily heated and compressed and the shock would start the thermonuclear reaction prematurely.

This was a true hydrogen bomb, but most of the yield came from nuclear fission rather than nuclear fusion. In a third series with a single test, known as Grapple Y, in April 1958, another design was tested. With an explosive yield of about , it remains the largest British nuclear weapon ever tested. The design of Grapple Y was notably successful because much of its yield came from its thermonuclear reaction instead of fission of a heavy uranium-238 tamper, making it a true hydrogen bomb, and because its yield had been closely predicted—indicating that its designers understood what they were doing.

Air Vice Marshal John Grandy succeeded Oulton as Task Force commander. The bomb was dropped off Christmas at 10:05 local time on 28 April 1958 by a Valiant piloted by Squadron Leader Bob Bates. It had an explosive yield of about , and remains the largest British nuclear weapon ever tested. The design of Grapple Y was successful because much of its yield came from its thermonuclear reaction instead of fission of a heavy uranium-238 tamper, making it a true hydrogen bomb, and because its yield had been closely predicted—indicating that its designers understood what they were doing.

The Ivy Mike bomb was a factory-like building, rather than a deliverable weapon. At its center, a very large cylindrical, insulated vacuum flask or cryostat, held cryogenic liquid deuterium in a volume of about 1000 liters (160 kilograms in mass, if this volume had been completely filled). Then, a conventional atomic bomb (the "primary") at one end of the bomb was used to create the conditions of extreme temperature and pressure that were needed to set off the thermonuclear reaction. Within a few years, so-called "dry" hydrogen bombs were developed that did not need cryogenic hydrogen.

Early ideas of the fusion bomb came from espionage and internal Soviet studies. Though the espionage did help Soviet studies, the early American H-bomb concepts had substantial flaws, so it may have confused, rather than assisted, the Soviet effort to achieve nuclear capability. The designers of early thermonuclear bombs envisioned using an atomic bomb as a trigger to provide the needed heat and compression to initiate the thermonuclear reaction in a layer of liquid deuterium between the fissile material and the surrounding chemical high explosive. The group would realize that a lack of sufficient heat and compression of the deuterium would result in an insignificant fusion of the deuterium fuel.

Andrei Sakharov's study group at FIAN in 1948 came up with a second concept in which adding a shell of natural, unenriched uranium around the deuterium would increase the deuterium concentration at the uranium-deuterium boundary and the overall yield of the device, because the natural uranium would capture neutrons and itself fission as part of the thermonuclear reaction. This idea of a layered fission-fusion- fission bomb led Sakharov to call it the sloika, or layered cake. It was also known as the RDS-6S, or Second Idea Bomb.The American counterpart to this idea was Edward Teller's Alarm Clock design of August 1946.

From 1993 to 1999, he was first deputy supervisor of VNIIEF. Trutnev began development of nuclear devices for industrial civilian purposes such as reservoir creation and gas field intensification, and devices which released very low amounts of ionising radiation. Yevgeny Avrorin described Trutnev producing the first "clean" nuclear charge, "a purely thermonuclear reaction" from a solid compound. Employees at Arzamas-16, including Trutnev, were upset that on a visit by Edward Teller and Siegfried S. Hecker (then director of the Los Alamos National Laboratory) to Russia after the break-up of the U.S.S.R., each was photographed in front of a model of the RDS-220 alongside scientists in Snezhinsk.

This was done with the introduction of the channel filler – an optical element used as a refractive medium, also encountered as random-phase plate in the ICF laser assemblies. This medium was a polystyrene plastic foam filling, extruded or impregnated with a low- molecular-weight hydrocarbon (possibly methane gas), which turned to a low-Z plasma from the X-rays, and along with channeling radiation it modulated the ablation front on the high-Z surfaces; it "tamped" the sputtering effect that would otherwise "choke" radiation from compressing the secondary. The reemitted X-rays from the radiation case must be deposited uniformly on the outer walls of the secondary’s tamper and ablate it externally, driving the thermonuclear fuel capsule (increasing the density and temperature of the fusion fuel) to the point needed to sustain a thermonuclear reaction. (see Nuclear weapon design).

The internal heating within stars is so great that (after an initial phase of gravitational contraction) they ignite and sustain thermonuclear reaction of hydrogen (with itself) to form helium, and can make heavier elements (see Stellar nucleosynthesis). The Sun for example has a core temperature of 13,600,000 K. The more massive and older the stars are, the more internal heating they have. During the end of its lifecycle, the internal heating of a star increases dramatically, caused by the change of composition of the core as successive fuels for fusion are consumed, and the resulting contraction (accompanied by faster consumption of the remaining fuel). Depending upon the mass of the star, the core may become hot enough to fuse helium (forming carbon and oxygen and traces of heavier elements), and for sufficiently massive stars even large quantities of heavier elements.

Two supernovae have been detected in Centaurus A. The first supernova, named SN 1986G, was discovered within the dark dust lane of the galaxy by R. Evans in 1986. It was later identified as a Type Ia supernova, which forms when a white dwarf's mass grows large enough to ignite carbon fusion in its center, touching off a runaway thermonuclear reaction, as may happen when a white dwarf in a binary star system strips gas away from the other star. SN 1986G was used to demonstrate that the spectra of type Ia supernovae are not all identical, and that type Ia supernovae may differ in the way that they change in brightness over time. The second supernova, dubbed SN2016adj, was discovered by Backyard Observatory Supernova Search in February 2016 and was initially classified as a Type II supernova based on its H-alpha emission line.

This work, in turn, evolved from his fundamental discovery of quantum tunneling as the mechanism of nuclear alpha decay, and his application of this theory to the inverse process to calculate rates of thermonuclear reaction. At first, Gamow believed that all the elements might be produced in the very high temperature and density early stage of the universe. Later, he revised this opinion on the strength of compelling evidence advanced by Fred Hoyle and others, that elements heavier than lithium are largely produced in thermonuclear reactions in stars and in supernovae. Gamow formulated a set of coupled differential equations describing his proposed process and assigned, as a PhD dissertation topic, his graduate student Ralph Alpher the task of solving the equations numerically. These results of Gamow and Alpher appeared in 1948 as the Alpher–Bethe–Gamow paper.Alpher, R. A., Bethe, H., Gamow, G., (1948), Phys. Rev., April 1. The inclusion of Bethe's name is explained at αβγ paper.