  Charge state distributions of various projectile ions passing through thin
carbon foils have been studied in the energy range of 0.7-3.0 MeV/u using x-ray
spectroscopy. This technique is found to be appropriate to segregate the charge
state distribution in the bulk from that of the surface by measuring the charge
changing phenomena right at the interaction zone i.e. at t=0. This observation
has been confirmed by different theoretical approaches. Surprisingly, it is
found that the charge state distribution measured in the bulk, exhibits
Lorentzian profile which is an important characteristic of any plasma. The
occurrence of such behaviour suggests that ion-solid collisions constitute
tenuous plasma in the bulk of the solid target. Thus, this work is expected to
have practical implications in various fields, in particular, plasma physics
and astrophysics.
