Transmutations of Aluminum by Deutons

Aluminum bombarded by 2.2 mv deutons is found to emit protons, neutrons and alpha-particles, presumably accompanying reactions in which Al²⁸ (radio-aluminum), Si²⁸ and Mg²⁵ are formed. The protons are the most abundant (about 8 per 10⁷ deutons) and have a complex spectrum of ranges, in which groups with ranges 10, 21, 30 and 53 cm have been resolved. The maximum range of 62 cm corresponds to a reaction energy of 5.3 mv. The radioactive product, shown chemically to be an aluminum isotope, decays with a half-life of 156±{}5 sec., emitting negative electrons and intense gamma-rays. The maximum range of the electrons is 0.95 g/cm² of Al, corresponding to an energy limit of 2 mv. The excitation curve for the radioactivity agrees with Gamow's theory of nuclear penetration. The alpha-particles have a range of 6.5 cm, giving a reaction energy of 6.6 mv for the formation of Mg²⁵. They are only 1/100 as abundant as the protons.