28Mg can be produced in 27Al(a,3p)28Mg or in 26Mg(t, p)28Mg nuclear reactions. Its half-life is 20.9 h, and it emits negative beta particles.

8.6.3 Aluminum-28

For the nuclear reactions and in the neutron-activation analysis (see Section 9.2.2.1) the target or the sample is placed into aluminum holders since irra­diation of aluminum with neutrons (27Al(n, Y)28Al) produces radioisotope with a short half-life (2.8 min). 28Al emits (3_ and gamma radiation. As a by-product, Na-24 is formed in the 27Al(n, a)24Na nuclear reaction. A negative conclusion of this reaction is the long time gamma radiation of the aluminum sample holders after irradiation in nuclear reactors.

Al-28 can be obtained from 28Mg/28Al generators too.