We provide the experimental evidence that the single electron capture process in slow collisions between O 3+ ions and neon dimer targets leads to an unexpected production of low-energy electrons. This production results from the interatomic Coulombic decay process, subsequent to inner shell single electron capture from one site of the neon dimer. Although pure one-electron capture from inner shell is expected to be negligible in the low collision energy regime investigated here, the electron production due to this process overtakes by one order of magnitude the emission of Auger electrons by the scattered projectiles after double-electron capture. This feature is specific to low charge states of the projectile: similar studies with Xe 20+ and Ar 9+ projectiles show no evidence of inner shell single-electron capture. The dependence of the process on the projectile charge state is interpreted using simple calculations based on the classical over the barrier model. PACS numbers: 34.70.+e, 34.10.+x, 36.40.Mr, 32.80.Hd, When an atom or a molecule loses an electron from an inner-valence state, the excitation energy is usually not sufficient to remove a second electron. The resulting decay processes are thus limited to photon emission and molecular dissociation. However, if this inner-shell ionization occurs in the vicinity of another atom or molecule, it was theoretically predicted that a new decay channel called interatomic Coulombic decay (ICD) could open up [1]. In this decay process, the energy resulting from a valence electron filling the inner-shell vacancy is transferred to the neighboring atom or molecule, where a low energy secondary electron is emitted. ICD was first observed in photoionization experiments for Ne clusters and dimers [2,3], and soon after for a large variety of rare gas clusters (see [4,5] and references therein) and for more complex systems such as water clusters [6,7].As already demonstrated in [8], ICD can also be induced by fast ion impact leading to inner-shell ionization. Being responsible for an additional production of low energy electrons (LEEs), it was pointed out that the ICD process could have a significant contribution in ioninduced radiation damage [9]. LEEs with energies bellow ionization thresholds induce bond cleavage in DNA bases, base-sugar, and sugar-phosphate units by dissociative electron attachment or dissociative electronically excited states production [10][11][12]. They can therefore be associated to an increased biological effectiveness of the ionizing radiation. In fast collisions (with projectile velocities v p larger than the valence electrons velocities v e ) involving 0.1625 MeV/u He + projectiles, it has been shown that, due to ICD, the yield of secondary LEEs below 2 eV was increased by a factor 14 when using Ne 2 dimer targets as compared to Ne atomic targets [9]. Complementary experiments with 11.37 MeV/u S 14+ , 0.150 MeV/u He 2+ and 0.125 MeV/u He + projectiles colliding on Ne 2 and Ar 2 dimer targets have confirmed the strong enhancement of LEEs product...

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