The paper reports on experiments carried out at JET to test the possibility of using some activating materials (e.g. 89Y, 167Er, 204Pb, 180Hf, 111Cd, etc.) to perform multi-foil neutron activation measurements. It is shown that apart from indium other materials can be successfully used in these measurements delivering more exact information about fluxes and also energy spectra of the analysed neutrons. These and other materials have threshold energy in the interesting energy range (0.5 - 15 MeV) and relatively large cross sections for the nuclear reactions, but have not been used in the activation measurements supposedly because produce daughter nuclides with a relatively short half-life time. We propose then some modification of the JET activation system mainly in order to convey the activation samples faster to the detector.
