Angular and high-frequency analysis of electron interference structures in ∼60 MeV/u Kr34+ + H2 collisions
Résumé
Detailed analyses of previous measurements, combined with additional measurements reported here, have been made of electron interference structures observed in 60 MeV/u Kr34+ + H2 collisions. Results are used to characterize the angular dependence of the primary interference structures over a wide range of electron ejection angles, particularly backward angles, and, additionally, to search for high-frequency structures as reported recently for 1–5 MeV/u H+ + H2 collisions [Hossain et al., Phys. Rev. A 72, 010701(R) (2005)]. The data for backward ejection angles, in combination with earlier data, permit a detailed comparison with theory over the range 30°–150°, showing that none of the existing theories predict accurately the observed oscillation frequencies for backward angles. Electron spectra for 90° and 150° taken in small energy steps and with improved statistics compared to earlier measurements were examined by means of a Fourier analysis but no evidence of the high-frequency structures reported for H+ + H2 collisions was found.