A helion (symbol h) is the nucleus of a helium atom, a doubly positively charged cation.
The term helion is a portmanteau of helium and ion, and in practice refers specifically to the nucleus of the helium-3 isotope, consisting of two protons and one neutron.
This particle is the daughter product in the beta-minus decay of tritium, an isotope of hydrogen:[citation needed] CODATA reports the mass of a helion particle as mh = 5.0064127862(16)×10−27 kg[1] = 3.014932246932(74) Da.
[2] Helions are intermediate products in the proton–proton chain reaction in stellar fusion.
An antihelion is the antiparticle of a helion, consisting of two antiprotons and an antineutron.