Tritium fusion with deuterium

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

C22-0117. Suppose that fusion of tritium and deuterium invoives two nuciei with equai kinetic energies totaiing 75% of the eiectricai repuision barrier. Caicuiate their speeds. 

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. 

While a deuterium-tritium (D-T) mix is the fuel of choice for sustained fusion research, tritium on Earth is scarce. Produced by cosmic ray protons colliding with nitrogen in the upper atmosphere, trace amounts are found in air and less abundantly in water.That is where lithium comes in. Bombarding lithium 6 or lithium 7 atoms with high-energy neutrons results in atoms of tritium and helium. 

Deuterium, either mixed with tritium or in the form of Li deuteride, LiD, is an essential ingredient in the fuel proposed for fusion power reactors. In the magnetically confined type of fusion power system, the working substance is a plasma mixture of fully ionized deuterium and tritium. In the laser or electron beam imploded type of system, the fuel form is a small sphere containing deuterium and tritium or LiD. Although power systems of these types have not yet been proved feasible, their successful development would create a market for deuterium and Li as great as the current market for eruiched uranium. 

Nuclear fusion became important on Farth with the development of hydrogen bombs. A core of uranium or plutonium is used to initiate a fission reaction that raises the core s temperature to approximately 10 K, sufficient to cause fusion reactions between deuterium and tritium. In fusion bombs, LiD is used as Li reacts with fission neutrons to form tritium that then undergoes fusion with deuterium. It is estimated that approximately half the energy of a 50 megaton thermonuclear weapon comes from fusion and the other half from fission. Fusion reactions in these weapons also produce secondary fission since the high energy neutrons released in the fusion reactions make them very efficient in causing the fission of... 

Some molecules look really peculiar. They may contain a muon instead of an electron. A muon is an unstable particle with the charge of an electron and mass equal to 207 electronic masses. For such a mass, assuming that nuclei are infinitely heavier than muon looks like a very bad approximation. Therefore, the calculations need to be non-adiabatic. The first eomputations for muonic molecules were performed by Kolos, Roothaan, and Sack in 1960. The idea behind the project was mnon-catalyzed fusion of deuterium (d) and tritium (t) the abbreviations here pertain to the nnclei only. This fascinating problem was proposed by Andrei Sakharov. Its essence is as follows. 

Theoretically, it is possible to obtain energy by the fusion of light atoms, e.g. deuterium with tritium. However, tritium has to be made from lithium, and this is also present in restricted amounts, sufficient to yield energy equivalent to about 60% of our fossil Sun reserves. The fusion of deuterium and deuterium would give virtually unlimited reserves of energy and if the physicists ever succeed in this, they have made a sun on earth, and the energy crisis will be over. 

Nevertheless, the oceans of the world are such huge reservoirs of water that the amount of DjO is significant. Nuclear fusion reactors would use deuterium as a fuel (along with tritium, the still heavier isotope of hydrogen), but the technological obstacles to the successful development of commercial fusion reactors have never been overcome. If these obstacles were overcome in the future, there is enough deuterium in the waters of the world s oceans to supply the needs of fusion reactors for thousands of years. 

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. 

Deuterium occurs naturally, mixed m with plain hydrogen in the tiny proportion of 0.015 percent in other words, plain hydrogen is the more common isotope by a factor of 6,600. Tritium for fusion energy can be created from another nuclear process involving the interaction of the neutron (in the equation above) with lithium ... 

Another approach to nuclear fusion is shown in Figure 19.6. Tiny glass pellets (about 0.1 nun in diameter) filled with frozen deuterium and tritium serve as a target. The pellets are illuminated by a powerful laser beam, which delivers 1012 kilowatts of power in one nanosecond (10 9 s). The reaction is the same as with magnetic confinement unfortunately, at this point energy breakeven seems many years away. 

The fission of one mole of uranium-235 produces more energy than the fusion of one mole of deuterium with one mole of tritium. What if you compare the energy that is produced in terms of mass of reactants Calculate a ratio to compare the energy that is produced from fusion and fission, per gram of fuel. What practical consequences arise from your result ... 

The fusion of deuterium produces another hydrogen isotope called tritium, H, along with common hydrogen, jH. The fusion of deuterium may also produce helium according to the reaction ... 

A potential major source of energy for the mid- to late-21st century is nuclear fusion. In todays experimental fusion reactors, deuterium and tritium atoms (both isotopes of hydrogen) fuse to create helium and fast-flying neutrons. The neutrons escape from the reaction chamber, carrying with them vast amounts of kinetic energy. 

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). 

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