Deuterium thermonuclear reaction

In view of the success of von Neumann s machine-based hydrodynamics in 1944, and at about the time when the fission bomb was ready, some scientists at Los Alamos were already thinking hard about the possible design of a fusion bomb. Von Neumann invited two of them, Nicholas Metropolis and Stanley Frankel, to try to model the immensely complicated issue of how jets from a fission device might initiate thermonuclear reactions in an adjacent body of deuterium. Metropolis linked... 

Essentially all deuterium in the Universe is believed to come from BBNS, because thermonuclear reactions in stars only cause net destruction of D and it is vastly... 

The D/H ratio of the sun is essentially zero all the primordial deuterium originally present has been converted into He dnring thermonuclear reactions. Analysis of primitive meteorites is the next best approach of estimating the hydrogen isotope composition of the solar system. 

It was detected by Urey, Brickwedde and Murphy in 1932. It occurs in all natural compounds of hydrogen including water, as well as in free hydrogen molecules at the ratio of about one part per 6,000 parts hydrogen. The principal application of deuterium is in tracer studies for measuring rates and kinetics of chemical reactions. It also is used in thermonuclear reactions and as a projectile in cyclotrons for bombardment of atomic nuclei to synthesize isotopes of several transuranium elements. Deuterium oxide, D2O, or heavy water is used as a neutron moderator in nuclear reactors. 

Bob s description of the energy-producing fusion of hydrogen to produce helium is correct, but a simplification of the actual process. The proton-proton reaction is actually a chain of thermonuclear reactions that are the main energy sources for the Sun and cool, Main Sequence stars.13 In the first step of the reaction, two hydrogen nuclei H (shown as two protons, each symbolized by + in the rectangle of figure 7.10) combine to form deuterium 2H. One of the... 

It is evident that fusion reactions become possible only at very high temperatures, and they are therefore called thermonuclear reactions. It is assumed that the deuterium cycle (a) prevails in the sun and in relatively cold stars, whereas the carbon cycle (b) dominates in hot stars. In the centre of stars densities of the order of lO g/cm and temperatures of the order of 10 K may exist, and under these conditions other thermonuclear reactions become possible ... 

In laser- and particle-beam-driven ICF, a millimetre-scale capsule of deuterium and tritium (D-T) would be imploded to create a sufficiently high density (-10 g cm ) and temperature (-10 keV) at the centre to ignite the thermonuclear reaction D-(-T He+n-i-17.6 MeV. The fusion burn would then propagate through the surrounding... 

The other luminaries enlisted for the summer study were Van Vleck, the Swiss-bom Stanford theoretician Felix Bloch, Oppenheimer s former student and close collaborator Robert Serber, a young Indiana theoretician named Emil Konopinski and two postdoctoral assistants. Konopinski and Teller had arrived at the Met Lab at about the same time earlier that year. We were newcomers in the bustling laboratory, Teller writes in a memoir, and for a few days we were given no specific jobs. Teller proposed that he and Konopinski review his calculations that seemed to prove the impossibility of using an atomic bomb to ignite a thermonuclear reaction in deuterium ... 

Teller had examined two thermonuclear reactions that fuse deuterium nuclei to heavier forms and simultaneously release binding energy. Both required that the deuterium nuclei be hot enough when they collided—energetic enough, violently enough in motion—to overcome the nuclear electrical barrier that usually repels them. The minimum necessary energy... 

It was assumed that only the most energetic of several possible [thermonuclear] reactions would occur, and that the reaction cross sections were at the maximum values theoretically possible. Calculation led to the result that no matter how high the temperature, energy loss would exceed energy production by a reasonable factor. At an assumed temperature of three million electron volts [compare the 35,000 eV known for D + D] the reaction failed to be self-propagating by a factor of 60. This temperature exceeded the calculated initial temperature of the deuterium reaction by a factor of 100, and that of the fission bomb by a larger factor The impossibility of igniting the atmo-... 

In this connection I should like to point out that [fission] gadgets of reasonable efficiency and suitable design can almost certainly induct significant thermonuclear reactions in deuterium even under conditions where these reactions are not self-sustaining It is not at all clear whether we shall ac-... 

Fusion is appealing as an energy source because of the availability of light isotopes on Earth and because fusion products are generally not radioactive. Despite this fact, fusion is not presently used to generate energy. The problem is that, in order for two nuclei to fuse, high temperatures and pressures are needed to overcome the electrostatic repulsion between them. Fusion reactions are therefore also known as thermonuclear reactions. The lowest temperature required for any fusion is about 40,000,000 K, the temperature needed to fuse deuterium and tritium ... 

Laser-Assisted Thermonuclear Fusion. An application with great potential importance, but which will not reach complete fmition for many years, is laser-assisted thermonuclear fusion (117) (see Fusion energy). The concept iavolves focusiag a high power laser beam onto a mixture of deuterium [7782-39-0] and tritium [10028-17-8] gases. The mixture is heated to a temperature around 10 K (10 keV) (see Deuterium AMD tritium). At this temperature the thermonuclear fusion reaction... 

Tritium is produced in heavy-water-moderated reactors and sometimes must be separated isotopicaHy from hydrogen and deuterium for disposal. Ultimately, the tritium could be used as fuel in thermonuclear reactors (see Fusionenergy). Nuclear fusion reactions that involve tritium occur at the lowest known temperatures for such reactions. One possible reaction using deuterium produces neutrons that can be used to react with a lithium blanket to breed more tritium. 

Pulsed plasmas containing hydrogen isotopes can produce bursts of alpha particles and neutrons as a consequence of nuclear reactions. The neutrons are useful for radiation-effects testing and for other materials research. A dense plasma focus filled with deuterium at low pressure has produced 10 neutrons in a single pulse (76) (see Deuterium AND TRITIUM). Intense neutron fluxes also are expected from thermonuclear fusion research devices employing either magnetic or inertial confinement. 

It IS often stated that unclear fusion tvill produce no radioactive hazard, but this is not correct. The most likely fuels for a fusion reactor would be deuterium and radioactive tritium, which arc isotopes of hydrogen. Tritium is a gas, and in the event of a leak it could easily be released into the surrounding environment. The fusion of deuterium and tritium produces neutrons, which would also make the reactor building itself somewhat radioactive. However, the radioactivity produced in a fusion reactor would be much shorter-lived than that from a fission reactor. Although the thermonuclear weapons (that use nuclear fusion), first developed in the 1950s provided the impetus for tremendous worldwide research into nuclear fusion, the science and technology required to control a fusion reaction and develop a commercial fusion reactor are probably still decades away. 

Temperatures in the range of 20 to 100 million degrees Celsius are required for fusion reactions. For this reason, a hydrogen bomb is triggered by a conventional fission atomic bomb. The atomic bomb produces the tremendous heat necessary to fuse hydrogen nuclei therefore, fusion bombs are often referred to as thermonuclear. The United States exploded the first hydrogen bomb on Eniwetok Atoll in the Pacific Ocean on November 1, 1952. This bomb was based on the fusion of deuterium ... 

Deuterium (2D) and tritium (3T) are heavier isotopes of hydrogen. The former is stable and makes up about 0.015 per cent of all normal hydrogen. Its physical and chemical properties are slightly different from those of the light isotope Tl For example, in the electrolysis of water H is evolved faster and this allows fairly pure D2 to be prepared. Tritium is a radioactive b-emitter with a half-life of 12.35 years, and is made when some elements are bombarded with neutrons. Both isotopes are used for research purposes. They also undergo very exothermic nuclear fusion reactions, which form the basis for thermonuclear weapons (hydrogen bombs) and could possibly be used as a future energy source. 

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