Proton activation analysis has been applied to develop a procedure for the simultaneous determination of chromium, nickel
and copper. The procedure involves the bombardment of the sample with protons to induce52Cr(p, n)52mMn,60Ni(p, n)60Cu and63Cu(p, n)63Zn reactions. These reactions have been studied for proton energies from 11 MeV to 15 MeV. Thick target yields for the production
of the indicator radionuclides as well as the sensitivities of the determination have been measured in this energy region
and are compared with results obtained for other charged particle induced reactions. Detailed data are given on nuclear and
instrumental interferences. The trace elements have been determined nondestructively and simultaneously in cobalt with a relative
precision of 8 to 15%.