Deuterium-tritium fusion reaction

Fusion research currently relies on the deuterium-tritium fusion reaction to produce useable power, a method that is well understood but still highly ineKI dent—much more energy must be put into the process than is produced. Fusion is not expected to be a viable source of power for humankind for at least the next 50 years. 

Of the several fusion reactions, deuterium tritium fusion is the most feasible, as it has the lowest ignition temperature, 40 million°K. (See Reaction 1.) Deuterium comprises 0.15... 

The fusion reaction least difficult to initiate is the deuterium-tritium (DT) reaction which releases a 14.1 MeV neutron and a 3.5 MeV alpha particle. However, because neutrons activate the reactor structure, other fusion reactions have been considered. These reactions are either neutron free, or they produce fewer and less energetic neutrons. The required quality of confinement for these more desirable fusion reactions is much higher than for DT, and it is not yet clear if it will be achieved. Hence, fusion reactor designers have concentrated on the DT reaction for at least the first generation of fusion plants. 

Deuterium-tritium fusion is considered the most likely process to result in a fusion reactor suitable for electricity production. In this process, a confined gas of deuterium and tritium atoms must be heated to nearly 100,000,000 K. Each fusion of D with T produces a helium nucleus, or alpha particle, and a neutron. The 17.6 million electron volts (MeV) of energy released per reaction are substantial, but only 3.5 MeV are carried away by the charged particle—the more useable form of energy for electricity. Although the method is well understood, it is still highly inefficient much more energy must be put into the process than is produced. Fusion is not expected to be a viable source of power for humankind for at least the next 50 years. 

Of the several fusion reactions, deuterium-tritium fusion is the most feasible, as it has the lowest ignition temperature, 4E7 "K. (See Reaction 1.) Deuterium comprises 0.15 percent of naturally occurring hydrogen, whereas tritium is produced by neutron fission of iithium-6 that is irradiated in a blanket surrounding a nuclear reactor core. Nuclide separation is required to produce the deuterium and possibly the lithium. The... 

The reactions of deuterium, tritium, and helium-3 [14762-55-17, He, having nuclear charge of 1, 1, and 2, respectively, are the easiest to initiate. These have the highest fusion reaction probabiUties and the lowest reactant energies. 

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. 

Nuclear Fusion Reactions. Tritium reacts with deuterium or protons (at sufftciendy high temperatures) to undergo nuclear fusion ... 

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. 

The most plausible fusion reaction for producing energy commercially involves two isotopes of hydrogen, deuterium (D) and tritium (T), or H and H. Deuterium contains one proton and one neutron for an atomic number of two. Tritium contains one proton and two neutrons for an atomic number of three. The reaction is... 

Another result of the cold-fusion epopee that was positive for electrochemistry are the advances in the experimental investigation and interpretation of isotope effects in electrochemical kinetics. Additional smdies of isotope effects were conducted in the protium-deuterium-tritium system, which had received a great deal of attention previously now these effects have become an even more powerful tool for work directed at determining the mechanisms of electrode reactions, including work at the molecular level. Strong procedural advances have been possible not only in electrochemistry but also in the other areas. 

One example of a fusion reaction is the fusion of deuterium and tritium. 

This reaction is a fusion reaction. It shows two light nuclei combining to form one heavy nucleus. This reaction fuels the sun. The two hydrogen reactants are atypical because they re rare isotopes of hydrogen, called tritium and deuterium, respectively. 

To initiate such a D-T fusion reaction requires temperatures of 10-100 million degrees. Relatively large amounts of deuterium/tritium and/or lithium deuteride can be heated to such temperatures by a fission explosion where the temperature may be 108 K. (Tritium is generated in situ by the neutron bombardment of i during the fusion reaction by the reaction 6Li + n —> 3H + 4He + n + 17 MeV, thus making the overall fusion reaction 6Li + 2H —> 2 4He + 21.78 MeV). 

Fusion is what powers the Sun and stars. One type of fusion reaction involves the combination of two "heavy" isotopes of hydrogen. Isotopes of an element have the same number of protons, but a different number of neutrons. For example, hydrogen and its isotopes—deuterium and tritium—all have one proton in their nuclei. Remember that the number of protons plus the number of neutrons make up the mass of an atom. Because they have different numbers of neutrons, hydrogen, deuterium, and tritium have different masses. Deuterium has one proton and one neutron. It has a mass of 2 atomic mass units (amu). Deuterium can also be written as hydrogen-2. The number following the element s name is the isotope s mass. Tritium has one proton and two neutrons. So, tritium has a mass of 3 amu. Tritium can be written as hydrogen-3. 

The simplest nuclear fusion reaction is the combination of the isotopes of hydrogen (deuterium and tritium) to form the heavier nucleus of helium. 

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. 

A single muon stopped in a target of deuterium-tritium mixture can catalyze more than 100 fusions, but this number is limited by two major bottle-necks. One is the rate at which a muon can go through the catalysis cycle before its decay (cycling rate), and another is a poisoning process called p-a sticking in which, with a probability u)s < 0.01, the muon gets captured after the fusion reaction to atomic bound states of the fusion product 4He, and hence lost from the cycle (see Section 5). 

Three promising fusion reactions are D-D (deuterium-deuterium) and D-T (deuterium-tritium) reactions ... 

High-temperature hydrogen plasmas, in addition to being a key component in energy projects of the nuclear fusion reaction using deuterium and/or tritium, have also been studied as agents for chemical reactions. 

When deuterium and tritium fuse, helium is formed and a burst of tremendous energy is created. The energy produced by the hydrogen bomb, the sun, and the stars is the result of fusion reactions. 

The focus of contemporary fusion research is the deuterium-tritium reaction ... 

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