Radiative decay following low energy charge exchange collisions at the Agrippa facility

From radiative decay observed in the X and VUV domain, it is possible to determine the (n, l) substate populations and deduce their excitation cross sections. We consider here the case of different projectiles of charge +8. For some of them, we show σ_nl for single capture from H ₂ and He, as a function of energy. From the spectra it is recognized that double capture followed by radiative decay is effective. Observed transitions — of the same nature as dielectronic recombination satellites — are the signature of this process. Finally, in the case where energy levels are not known since the capture is a selective process, radiative decay appears thus as a means for basic spectroscopic studies.