A method has been developed for determining silicon in aluminium by fast neutron activation. It is based on the separation
of two gamma lines by a Ge(Li) detector: the 1.73 MeV line from the product of27Al(n, α)24Na and the 1.78 MeV line from the28Si(n, p)28Al reaction. In the case of aluminium-silicon alloys 100 μg silicon can be determined, with an error of 10% in an aluminium
sample of 1 g.