Experimental study of stopping power for high Z ion in hydrogen

The stopping power of iodine ions traversing a windowless hydrogen target has been measured varying the gas in a large pressure range (10 −1–120 Torr). Experimental measurements present the energy losses and the charge distributions of emerging ions. Incident energies of iodine ion beams correspond to a domain where high-velocity approximation is valid. Stopping range extends up to 70% of the incident energy. Those results enable us to test stopping power theories at high velocity and large perturbation parameter Z/ V. Higher-order correction terms for the stopping, calculated with point-like approximation for the charge or with more realistic atomic potential are compared with experimental energy losses.