Observation of rapid evolution of convoy electron angular distributions

We present results of doubly differential cross-section measurements for production of convoy electrons from 36-MeV/u Ar ions in thin amorphous carbon targets. Comparison of convoy emission distributions as a function of target thickness reveals rapid evolution of component multipole strengths. Thin-target results are compared with binary ion-atom electron-loss-to-the-continuum predictions. A quantitative model of the multipole evolution bridging the transition from the single- to the plural-collision regime is presented which demonstrates significant competition between one-step and multistep production mechanisms