Dissociation of highly charged CO^q+(q>or=2) ions via non-Coulombic potential energy curves

Abstract

Formation and subsequent decay of very highly charged states of CO molecular ions has been studied in 97 MeV collisions between F8+ and CO using a crossed beams apparatus by measuring the energy distributions of carbon and oxygen ions. The kinetic energies released (KER) upon dissociation of COq+ (q=2-10) ions have been investigated by means of large scale, ab initio configuration interaction molecular orbital calculations. Results indicate that dissociation via non-Coulombic potential energy curves of COq+ ions yields lower values of KER than would be expected from purely Coulombic considerations due to the significance of electronic charge density distributions in the internuclear region.

Measurement of kinetic energy release in CO fragmentation by charge-changing collisions of fast heavy ions

“…As for the fragmentation of CO 3+ , the fragmentation channel (C + ,O 2+ ) shown in panel (c) are somewhat broader to higher KER compared with (C 2+ ,O + ) shown in panel (b). This is reasonable because the adiabatic potential energy of (C + ,O 2+ ) is known to be higher than the latter channel at R → ∞ [2]. This trend is also observed in other experimental results [11,14].…”

“…The solid square curves are theoretical spectra estimated from a simple Coulomb explosion model using E c = q 1 q 2 /R e , where E c is the central peak energy, q the charges of ion pairs, and R e the equilibrium internuclear distance of CO. The width W of the distribution is related to the probability density of the ground state of CO and may be estimated to the first approximation, as [4] [2,14,20].…”

“…Theoretical KER predicted from potential energy curves of possible electronic states [2,14,20] are listed in Table II and partly shown by vertical lines in Fig. 5.…”

“…In the last few decades collision-induced molecular fragmentation was extensively studied for various combinations between projectile particles and molecules [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. The investigation was carried out for the identification of fragment-ion pairs, kinetic energies of the fragments, and the orientation effect on the molecular fragmentation.…”

Potential energy curves for neutral and multiply charged carbon monoxide

“…The experimental value of 83.4 eV obtained from Auger spectra indicates the formation of the 2 Δ state under laboratory conditions[23,24].Potential energy curves for CO 4+ in 3 Σ − , 3 Π and 1 Δ states are illustrated in figure 1d. Here again there are two dissociative channels, one corresponding to C 2+ ( 1 S) + O 2+ ( 3 P) and the other corresponding to C 2+ ( 1 S) + O 2+ ( 1 D).…”