The apparatus mounted beside the Saclay variable-energy cyclotron to develop this new analytical technique is described. Photon emission yield measurements were carried out on copper, selenium and gold bombarded with 5 to 20 MeV protons and 10 to 28 MeV α-particles; the results obtained are given. The method is applied to the analysis of dusts collected on atmospheric sampling filters. These tests show that optimum experimental conditions are obtained by the use of 2 to 3 MeV protons or 8 to 12 MeV α-particles; it is established moreover that intrinsically the latter give the best results.