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Helium-3 (3 He [1] [2] see also helion) is a light, stable isotope of helium with two protons and one neutron. (In contrast, the most common isotope, helium-4, has two protons and two neutrons.) Helium-3 and protium (ordinary hydrogen) are the only stable nuclides with more protons than neutrons. It was discovered in 1939.
In stars, however, 3 He is more abundant, a product of nuclear fusion. Extraplanetary material, such as lunar and asteroid regolith, has traces of 3 He from solar wind bombardment. To become superfluid, 3 He must be cooled to 2.5 millikelvin, ~900 times lower than 4 He (2.17 K).
As helium-3 leaked from the core, it ascended to the surface through the mantle in the form of magma plumes that eventually erupted on Baffin Island. “During the eruption, the vast majority of ...
Helium 3 is rare on Earth, primarily produced by the radioactive decay of tritium, but it does reside in abundance in the lunar regolith, deposited by billions of years of solar wind. The isotope ...
By one estimate, the solar wind has deposited more than 1 million tons of helium-3 (3 He) on the Moon's surface. [62] Materials on the Moon's surface contain helium-3 at concentrations estimated between 1.4 and 15 parts per billion (ppb) in sunlit areas, [1] [63] [64] and may contain concentrations as much as 50 ppb in permanently shadowed ...
Similar cooling of helium-3, which has a lower boiling point, can achieve about 0.2 kelvin in a helium-3 refrigerator. Equal mixtures of liquid 3 He and 4 He below 0.8 K separate into two immiscible phases due to their dissimilarity (they follow different quantum statistics: helium-4 atoms are bosons while helium-3 atoms are fermions). [30]
Helium-3 nuclear magnetic resonance (3 He-NMR) is an analytical technique used to identify helium-containing compounds.Because a helium atom, or even two helium atoms, can be encased in fullerene-like cages, the nuclear magnetic resonance spectroscopy of this element can be a sensitive probe for changes of the carbon framework around it.
Police in Elizabethtown, Ky., say that Terrance Corbin, 20, was watching the child, as well as a 3-year-old, on Jan. 7 with no other adults present, according to a press release sent to PEOPLE.