Helium-4
A stable isotope of helium whose nucleus contains two protons and two neutrons. It is a boson and becomes a superfluid at 2.17 K. It is the most abundant helium isotope on Earth.
Timeline (last 90 days)
Helium-3 and helium-4 are the two stable isotopes of helium; a helium-4 nucleus contains 2 protons and 2 neutrons, while helium-3 contains 2 protons and 1 neutron.
Helium-4 transitions to a superfluid at 2.17K, whereas helium-3, being a fermion, has a superfluid transition temperature of about 0.002K.
Researchers are exploring alternative refrigeration schemes, such as refrigerators using helium-4 or adiabatic demagnetization refrigeration, but the performance of these methods at extremely low temperatures still falls short of dilution refrigerators.
All Facts (3)
Helium-3 and helium-4 are the two stable isotopes of helium; a helium-4 nucleus contains 2 protons and 2 neutrons, while helium-3 contains 2 protons and 1 neutron.
50%UnverifiedHelium-4 transitions to a superfluid at 2.17K, whereas helium-3, being a fermion, has a superfluid transition temperature of about 0.002K.
50%UnverifiedResearchers are exploring alternative refrigeration schemes, such as refrigerators using helium-4 or adiabatic demagnetization refrigeration, but the performance of these methods at extremely low temperatures still falls short of dilution refrigerators.
50%