Ionization of molecular hydrogen by 5 MeV/u bare fluorine ion and electron interference

Abstract

Electrons emitted from H2 in collisions with 5 MeV/u F9 + ions were measured in the energy range from 1 to 300 eV and a wide range of emission angles between 20° and 160°. The measured energy and Electrons emitted from H2 in collisions with 5 MeV/u F9+ ions were measured in the energy range from 1 to 300 eV and a wide range of emission angles between 20◦ and 160◦. The measured energy and angular distributions of double-differential cross sections (DDCSs) of these electrons are compared with the molecular continuum distorted wave-eikonal initial state (CDW-EIS) calculation. The observed energy and angular distributions can be explained, in general, with the help of the two-centre effect which is included in the CDW-EIS model. In addition, the DDCS ratios of molecular-to-atomic hydrogen exhibit an oscillatory structure which is discussed in terms of Young-type electron interference. We have obtained the frequencies of such oscillations and studied their angular dependence. The single-differential cross sections (SDCSs) are deduced by integrating the DDCSs over solid angle and emission energy. We demonstrate that the SDCS ratio spectra also preserve the signature of interference to some extent. The asymmetry parameter, derived only from the molecular cross sections for forward and backward angles, shows an oscillatory behaviour as a function of electron velocity. This is understood in terms of the interference effect superimposed with the post-collisional two-centre effect.these electrons are compared with the molecular continuum distorted wave-eikonal initial state (CDW-EIS) calculation. The observed energy and angular distributions can be explained, in general, with the help of the two-centre effect which is included in the CDW-EIS model. In addition, the DDCS ratios of molecular-to-atomic hydrogen exhibit an oscillatory structure which is discussed in terms of Young-type electron interference. We have obtained the frequencies of such oscillations and studied their angular dependence. The single-differential cross sections (SDCSs) are deduced by integrating the DDCSs over solid angle and emission energy. We demonstrate that the SDCS ratio spectra also preserve the signature of interference to some extent. The asymmetry parameter, derived only from the molecular cross sections for forward and backward angles, shows an oscillatory behaviour as a function of electron velocity. This is understood in terms of the interference effect superimposed with the post-collisional two-centre effect.