Fri May 29, 2009 9:17 pm
Re: Cacademia de stiinte
In January 2006, the Russian space company RKK Energiya announced that it considers lunar helium-3 a potential economic resource to be mined by 2020,[43] if funding can be found
Some fusion processes produce highly energetic neutrons which render reactor components radioactive through the continuous bombardment of the reactor's components with emitted neutrons. Because of this bombardment and irradiation, power generation must occur indirectly through thermal means, as in a fission reactor. However, the appeal of helium-3 fusion stems from the nature of its reaction products. Helium-3 itself is non-radioactive. The lone high-energy by-product, the proton can be contained using electric and magnetic fields. The momentum energy of this proton (created in the fusion process), will interact with the containing electromagnetic field; resulting in direct net electricity generation
The amounts of helium-3 needed as a replacement for conventional fuels should not be underestimated. The total amount of energy produced in the 21H + 32He reaction is 18.4 MeV, which corresponds to some 493 megawatt-hours (4.93x108 Wh) per three grams (one mole) of ³He. Even if that total amount of energy could be converted to electrical power with 100% efficiency (a physical impossibility), it would correspond to about 30 minutes of output of a thousand-megawatt electrical plant; a year's production by the same plant would require some 17.5 kilograms of helium-3.
The amount of fuel needed for large-scale applications can also be put in terms of total consumption: According to the US Energy Information Administration, "Electricity consumption by 107 million U.S. households in 2001 totaled 1,140 billion kWh" (1.14x1015 Wh). Again assuming 100% conversion efficiency, 6.7 tons of helium-3 would be required just for that segment of one country's energy demand, 15 to 20 tonnes given a more realistic end-to-end conversion efficiency
un tricou - doo tricoaie
