Spectra of argon recoil ions in the 9-85 nm wavelength range have been measured by impact of a heavy-ion beam on a neutral target. These spectra were analyzed by comparison with experimentally observed transitions, interpolations or extrapolations in isoelectronic sequences, theoretically calculated energy levels and quantum defect calculations. This led to identification of 417 lines and to determination of 75 new transitions, especially in argon VI and VII.

The impact of highly charged and high energy ions in a gas target produces excited recoil-ions. The speed of these ions being quite low, the Doppler shifts and broadening of emitted lines are very small. With a Kr20+ beam at 1.15 MeV/amu, we have observed the spectra of Ne ions in the wavelength range 60-570 Å and of Ar ions in the range 150-290 Å. In the first one, 130 lines have been identified, classified and compared to previous results. In the second one, 55 lines have been observed, 12 transitions unknown up to now are determined and compared to similar transitions for isoelectronic ions. The 3p4d configuration in Ar V is analysed, taking into account the intermediate coupling.

Time-of-flight spectrometers, currently used for charge state analysis of low-energy recoil ions produced in swift ion-atom collisions, are shown to provide, under specific conditions, charge state characteristic peaks whose shape directly reflects the distribution of the initial velocity component of the extracted ions along the extraction axis. Advantage is taken of this property to determine, with the help of a simple model for velocity distributions, the mean recoil energy of Ne 7+ to 9' and Ar 9' to 16' ions produced by a 27 MeVa.m.u.-' Xe 52' projectile beam.

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Production of multiply charged recoil ions by impact of swift highly charged projectiles is investigated. The first Born Plane Wave Approximation employed in the framework of the independent electron model (IEM) provides reasonable cross-sections for multiple ionization of rare gases by Krq+ (q ∼ 30) at 35 MeV/amu, which is a typical ion beam on the LISE ( 1) line at GANIL. Contribution of capture is investigated in the case of helium target