Elastic resonant and nonresonant differential scattering of quasifree electrons fromB4+(1s)andB3+(1s2)ions

Abstract

High-resolution doubly differential cross-section measurements and calculations for quasifree electrons elastically scattered through 180 deg. from ground-state He- and H-like boron ions are presented. The measurements, covering the entire (for B{sup 3+}) and (for B{sup 4+}) Rydberg series populated by resonant excitation, were performed by zero-degree Auger projectile electron spectroscopy of 3.91 MeV B{sup 4+} and 3.08-7.48 MeV B{sup 3+} ions in collisions with H{sub 2} targets. The projectile energy dependence study is used to further investigate other background contributions such as direct electron capture, direct excitation, and nonresonant transfer excitation. R-matrix calculations, particularly sensitive at this large scattering angle to electron correlation, exchange, and interference effects, are found to be in excellent overall agreement within the electron scattering model.