Fragmentation ofCO22+in collisions with low-energy electrons

Abstract

The fragmentation of the C022+ dication following 200 eV electron impact double ionization was studied using a cold target recoil-ion momentum spectroscopy. Both two-body and three-body fragmentation channels were observed with an ion-ion coincidence technique. The slopes of the peaks in the coincidence spectra were extracted and compared with previous results and theoretical predictions. Overall, good agreement between theoretical and experimental results was achieved, while different behaviors were observed for the channel of fragmentation into C+ + 0 + + O with previous high energy electron impact results. The momentum vectors of ionic fragments were measured, and thus the momentum vector of the neutral particle was deduced and kinetic energy release (KER) distributions for the different fragmentation channels were obtained. KER distribution behavior also shows a different signature from that induced by high energy electron impact. Furthermore, the three-body fragmentation mechanism, i.e., dissociation in one-or two-step processes, was distinguished from their distinct signatures on the Dalitz plots and the slopes of the islands from the covariance mapping spectrum. For example, the fragmentation channel C+ + 0+ + O was found to be very similar to the 60 eV photon impact result [

Strong-field-induced bond rearrangement in triatomic molecules

“…The intricacies in the fragmentation and isomerization of CO 2 can depend on the charge state of the ion [69][70][71][72][73][74], metastable states of the dication [75][76][77][78], the Renner-Teller effect [40,71] and the geometry of excited states [71,79]. As a result of these interesting features, CO 2 fragmentation has been examined using electron [77,[80][81][82][83] and ion impact [84][85][86] W/cm 2 in our measurement compared to 10 14 W/cm 2 in their measurement [26].…”

Dissociative ionization of N2by fast electron impact: roles of molecular orbitals

“…The experimental technique is based on the COLTRIMS setup at Fudan University and details of the setup have been described elsewhere [36][37][38]. Briefly, inside the ultrahigh vacuum collision chamber, a pulsed electron beam crosses perpendicularly with the cold gas target provided by the supersonic jet system.…”

Concerted and sequential three-body fragmentation of deep-core-ionized carbon disulfide

“…In particular, significant efforts have been made in the study of three-body fragmentation, using various ionizing sources such as synchrotron radiation, 2–5 intense lasers, 6–13 ion impact 14–19 and electron impact. 20–23 Most of these studies focused on the fragmentation dynamics of archetypal triatomic molecules, namely CO 2 , 4,10,13–16,20,21 OCS, 11,17,19,23 and CS 2 . 5–8,12,22 The challenging aspect of three-body fragmentation studies is the reconstruction of the dynamics and the difficulty that can arise to disentangle simultaneous or stepwise breakup mechanisms.…”