Recoil-ion charge-state-resolved electron-production cross sections at 55 degrees for 1 MeV/u C5+ on He and Ar.

Abstract

Recoil-ion charge-state-resolved doubly differential cross sections for ejecting electrons at \ensuremath{\sim}55\ifmmode^\circ\else\textdegree\fi{} with respect to the incident beam direction in collisions between 1 MeV/u ${\mathrm{C}}^{5+}$ projectiles and Ar and He targets have been measured. Electrons with kinetic energies between 100 and 1250 eV have been detected. A prominent feature in the electron energy distributions is the binary-encounter peak. Experimental results are compared with binary-encounter electron production cross sections obtained using the impulse approximation and with theoretical predictions from many-body classical trajectory Monte Carlo calculations. An enhancement in the fraction of electrons detected with singly charged He recoil ions and a corresponding decrease in the fraction detected in coincidence with doubly charged He recoil ions as a function of the electron energy have been observed near the binary-encounter electron energy. This structure has been predicted by recent many-body classical trajectory Monte Carlo calculations. \textcopyright{} 1996 The American Physical Society.