Charge Exchange Collision Experiments With Highly Charged Ions -Status Report-

In the collision of highly charged ions on atoms or simple molecules, one electron (or more) may be transferred to the projectile. It is observed that in the low velocity range (ν < ν 0 ), the one electron charge exchange cross-section is quasi energy independent at least in the energy range 2 q -10 q keV when q ⩾ 4. It is shown that a scaling law may be deduced from a series of measured values obtained with C q + , N q + , O q + , Ar q + , Xe q + , some of them up to completely stripped (C, N, O; Ar up to q = 16). Since the collision may be described along quasi-molecular approaches, it is known that the projectile after capture is left in excited states. An attempt is made to observe part of the radiative decay in the case of the capture of one electron by completely stripped C, O and Ne ions which are thus left hydrogenic and radiate in the soft X-ray range. The X-ray emission cross section is shown to be large and may be utilized to calculate the excitation cross-section for a given level.