helium-3
Sign in to savethumb|alt=The nucleus is depicted by two red circles with inscribed plus symbols and one purple circle with no inscription. Around the nucleus there is a black ring - a symbol of an electron shell. On it are two teal circles with inscribed minus symbols, depicting electrons.|Diagram of a Helium-3 atom Helium-3 (3He see also helion) is a light, stable isotope of helium with two protons and one neutron (in contrast to the more common isotope, helium-4, which has two protons and two neutrons.) Helium-3 and hydrogen-1 are the only stable nuclides with more protons than neutrons. It was discovered
Key facts
- Isotope.parent_mass
- 3
- Isotope.parent_decay
- beta decay of tritium
- Isotope.spin
- ħ
- Isotope.alternate_names
- tralphium (obsolete)
- Isotope.symbol
- He
- Isotope.mass_number
- 3
- Isotope.num_neutrons
- 1
- Isotope.num_protons
- 2
- Isotope.abundance
- 0.000137% (atmosphere)0.01% (Solar System)
- Isotope.halflife
- stable
- Isotope.image
- Angeregtes Helium 3.jpg
- Isotope.image_caption
- Electric discharge inside a glass ampule of low pressure Helium-3
- Isotope.parent
- Tritium
- Isotope.parent_symbol
- H
via Wikipedia infobox
Article
23 sectionsContents
- History
- Physical properties
- Superfluidity
- Natural abundance
- Terrestrial abundance
- Moon
- Gas giants
- Solar nebula (primordial) abundance
- Human production
- Tritium decay
- Uses
- Helium-3 spin echo
- Neutron detection
- Cryogenics
- Nuclear magnetic resonance
- Radio energy absorber for tokamak plasma experiments
- Nuclear fuel
- He-3 power plants
- Alternatives to He-3
- See also
- Notes and references
- Bibliography
- External links
thumb|alt=The nucleus is depicted by two red circles with inscribed plus symbols and one purple circle with no inscription. Around the nucleus there is a black ring - a symbol of an electron shell. On it are two teal circles with inscribed minus symbols, depicting electrons.|Diagram of a Helium-3 atom Helium-3 (3He see also helion) is a light, stable isotope of helium with two protons and one neutron (in contrast to the more common isotope, helium-4, which has two protons and two neutrons.) Helium-3 and hydrogen-1 are the only stable nuclides with more protons than neutrons. It was discovered in 1939. Helium-3 atoms are fermionic and become a superfluid at the temperature of 2.491 mK.
Helium-3 occurs as a primordial nuclide, escaping from Earth's crust into its atmosphere and into outer space over millions of years. It is also thought to be a natural nucleogenic and cosmogenic nuclide, one produced when lithium is bombarded by natural neutrons, which can be released by spontaneous fission and by nuclear reactions with cosmic rays. Some found in the terrestrial atmosphere is a remnant of atmospheric and underwater nuclear weapons testing.