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What is Helium-3 Fusion
Helium Helium-3 is an a one neutron isotope of helium that is formed as cosmic rays bombard Helium Helium-4 that is produced naturally through fusion in the sun. Unfortun Unfortunately ately the earth earth’s atmosphere and magnetic field repel helium s helium-3 and consequently there are very minimal quantities in existence on earth. Beside primor primordial deposits, small dial quantities of helium helium-3 can also be(What is Helium-3 Fusion)
attained as products of tritium decay from fission reactors and nuclear weapons.
Although these deposits on earth provide us with a minimal amount of fuel to run small experiments with, another more abundant source of helium helium-3 would be needed for us to actually use helium helium-3 for energy(What is Helium-3 Fusion)
thout a repulsive atmosphere, the moon has Without accumulated large amounts of heliumaccumulated helium–3 on its surface. An interesting statistic is that the amount of energy stored in lunar helium is 10 times the amount of energy stored in all of the fossil fuels on earth. Because the lunar heliumon helium–3 exists in concentrations of 13 parts per billion in the lunar soil, a significant amount of refining would need to occur on the moon in order to extract the heliumhelium–3 and maximize the amount that could be returned to earth on each trip. When it is considered that the Saturn V rockets used in the Apollo programApollo program
programcould liftcould liftoff with a payload of 50 tons, the notion of a bringing mining eoff equipment to the moon does quipment not seem completely unrealistic. In fact, the Chinese governmentnot governmenthas outlined plans to send has astronauts to the moon to lay the groundwork for establishing miastronauts mining colonies for heliumning helium–3. The plan is to have astronauts on the moon by 2009 and mining as earplan early as 2015.
Fundementals of the Reaction
The Combination of nuclei of Deuterium and Helium Helium-3 yields Hydrogen and Helium and an
Energy of 18.4 MeV per reaction(What is Helium-3 Fusion)
The notion of D D-T fusion being radioactively benign is a myth as the reaction produces high energy neutrons that activate the materials that compose the reactor, forcing components, especially the inner wall, to need frequent replacement,
D-He He-3 reactions produce no high energy neutrons, and consequently the activation of metals is drastically reduced. (Stray D D-D reactions will generate some neutrons)(What is Helium-3 Fusion)
Another significant benefit of using Deuterium and Helium Helium-3 fuels is that the reaction products, being charged particles, can be manipulat manipulated by ed electric and magnetic fields and can consequently used for direc direct energy t conversion.(What is Helium-3 Fusion)
Experiments have demonstrated that a blind like series of water cooled ion collectors can convert a high energy (100 KeV KeV) beam of ) ions into electrical energy with efficiencies on the order of 60 60-
70 percent. These efficiencies are much greater than with DT fuel or with fission reactors.
Conditions necessary for D D-He He-3 Fusion
As we have already learned, the amount of energy needed to fuse nuclei is proportional to the number of protons involved in the reaction. Because D D-He He-3 Fusion involves 3 protons as opposed to 2 with DT fusion, the amount of heat required for goo good fusion parameters is 100
d keV keV. This is about 10 times greater than the amount needed for DT f . fusion. At the Naka Fusion
usion. Center in Japan, scientists set the world record for the hottest plasma in their advanced
tokamak JT JT-60. This plasma reached 520,000,000 Kelvin, which corresponds to ion energies of 50 keV keV, showing that the energy requirements for helium , helium-3 fusion are not so farfetched.
Inertial Electrostatic Confinement
At the University of Wisconsin, researchers have developed a new small scale method of producing fusion. In electrostatic confinement, a small vacuum chamber is filled with gaseous fuel at a low pressure. An outer and inner grid are contained in the chamber and are charged such that there is a potential differenc difference o e 100kV between them. Ions oscillate in the center and reach very high energies, enough to force fusion upon collisiding with other nuclei.(What is Helium-3 Fusion)
Using deuterium and helium helium-3 fuels, scientists have shown successful fusion and generation of high energy protons on a small scale. The process would need to be greatly refined for energy production but has definitely been effective as a proof of concept.