Dipolar dissociation dynamics in electron collisions with carbon monoxide

Abstract

Dipolar dissociation processes in the electron collisions with carbon monoxide have been studied using time of flight (TOF) mass spectroscopy in combination with the highly differential velocity slice imaging (VSI) technique. By probing ion-pair states, both positive and/or negative ions may be detected. The ion yield curve of negative ions provides the threshold energy for the ion-pair production. On the other hand, the kinetic energy distributions and angular distributions of the fragment anion provide detailed dynamics of the dipolar dissociation process. Two ion-pair states have been identified based on angular distribution measurements using the VSI technique.

Effect of slicing in velocity map imaging for the study of dissociation dynamics

“…Weighting ratio of the partial waves a0 : a1 : a2 for Σ b1 : b2 : b3 for Π two kinetic energy bands (0.0 to 0.3 eV and 0.3 to 2.5 eV) in IPD range extracted using both the mentioned techniques. All the angular distributions are fitted using the expression given by Van Brunt [29] and are already discussed in detail in our previous report [1]. The best fit reveals that the final states of O − fragments are associated with Σ and Π symmetries as shown in Fig.…”

“…We use the CoboldPC software [22] to save the x & y coordinates along with the flight time (t) of all detected ions in a list-mode format (LMF). Others experimental details are briefly discussed in our previous reports [1,2]. layed start pulse and the detected ion signal.…”

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Inelastic collision dynamics between isolated gas-phase carbon monoxide molecules and low energetic electrons (< 50 eV) has been studied using state-of-the-art velocity map imaging apparatus and reported previously [1,2]. These were based on data analysis using the time-gated parallel slicing technique, which has recently revealed the drawback of lower momentum ion exaggeration mainly due to the inclusion of whole Newton sphere's of diameter ≤ parallel slicing time window.

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Absolute cross-sections of fragment negative ions in electron collisions with difluoromethane

“…Here the incident electron transfers some energy to the molecule and excites it to the ion-pair state that eventually dissociates into an anion and a cation. This ion-pair dissociation is possible as long as the energy of the incident electron is equal to or more than the excitation energy required because the extra energy is always carried out by the outgoing electron [20]. The IPD process in the present experiment can be expressed as…”

Dissociation dynamics in the dissociative electron attachment to ammonia molecule

“…Details of the experimental setup used for velocity slice images (VSI) are present in different papers [2,24]. In the present context we will discuss it briefly.…”