Charge exchange and stopping power of channeled heavy ions

We investigated the exit charge, scattering angle and energy loss distribution of heavy ions (30 MeV carbon) planar channeled in a thin crystal. We measured, in a list mode, exit charge q ex, scattering angle θ ex with respect to the (110) channeling plane, and energy loss ΔE, for each heavy ion of incident charge q in and incident angle θ in, and obtained a distribution Y( θ sc, q ex, ΔE; θ in, q in). As a single crystal, we adopted a thin totally depleted Si detector of 4 μm in thickness, and we measured the energy loss by the signal of the detector itself. After passing through the sample crystal, the exit charge and angle of the ions were measured with a 2D position sensitive detector coupled with a slit and an electrostatic deflector. Close correlations among the exit charge, energy loss and exit angle were found.