Alpha decay helium produced on Earth is the result of the alpha decay of underground deposits of minerals containing uranium or thorium. The helium is brought to the surface as a by-product of natural gas production. Alpha particles were first described in the investigations of radioactivity by Ernest Rutherford in 1899, and by 1907 they were identified as He ions. By 1928, George Gamow had solved the theory of alpha decay via tunneling. The alpha particle is trapped in a potential well by the nucleus. Classically, it is forbidden to escape, but according to the (then) newly discovered principles of quantum mechanics,
Americium-241 starting material for the production of other transuranic elements and transactinides – for example, neutron bombardment of Am yields Am: formula_3 From there, 82.7% of Am decays to Cm and 17.3% to Pu: 82.7% → formula_10 17.3%→ formula_11 In the nuclear reactor, Am is also up-converted by neutron capture to Am and Am, which transforms by β-decay to Cm: Irradiation of Am by C or Ne ions yields the isotopes Es (einsteinium) or Db (dubnium), respectively. Furthermore, the element berkelium (Bk isotope) had been first intentionally produced and identified by bombarding Am with alpha particles, in 1949, by the same