HZE ions are the high-energy nuclei component of galactic cosmic rays (GCRs) which have an electric charge of +3 e or greater – that is, they must be the nuclei of elements heavier than hydrogen or helium.
The abbreviation "HZE" comes from high (H), atomic number (Z), and energy (E). HZE ions include the nuclei of all elements heavier than hydrogen (which has a +1 e charge) and helium (which has a +2 e charge). Each HZE ion consists of a nucleus with no orbiting electrons, meaning that the charge on the ion is the same as the atomic number of the nucleus. Their source is not certain, but is thought likely to be supernova explosions.[1]