Kinetic-energy release inN2fragmentation by charge-changing collisions of2-MeV

Abstract

Collision-induced fragmentation of N 2 was investigated for 2-MeV C + ions under charge-changing conditions of C + → C q+ (q = 0,2,3). Coincidence measurement of fragment ions was performed by means of a momentum three-dimensional imaging technique at scattering angles of θ = 0 and 1.0 mrad. Kinetic-energy release (KER) obtained for a fragmentation channel of N 2+ 2 → N + + N + was found to differ significantly in electron loss and capture collisions. In two-electron-loss collisions (C + → C 3+ ), KER spectra were essentially identical for θ = 0 and 1.0 mrad. It is concluded that the energy level of dissociating excited states of N 2+ 2 may be saturated when the interaction strength, defined as q vb , exceeds 0.65, where q and v are the charge and the velocity, respectively, of an incident ion, and b is the impact parameter.

Formation of protons from dissociative ionization of methane induced by 54 eV electrons

“…Extensive studies of the ionization and dissociation of molecules have been carried out in previous studies by using various projectiles such as ions [1][2][3], photons [4][5][6][7], and electrons [8][9][10]. The main purposes of such studies are to investigate the various decay pathways and to clarify which parameters determine these decay pathways.…”

“…The main purposes of such studies are to investigate the various decay pathways and to clarify which parameters determine these decay pathways. Previous ion impact experiments [1][2][3] show that the amount of energy deposited into the target molecules is the key parameter that determines the decay pathways, and this energy deposition depends strongly on the projectile's properties (element, charge and velocity, etc.). In contrast to ion impact, the amount of energy absorbed by the target for electron impact is mainly influenced by the electron velocity.…”

Velocity and charge-state dependence on the Coulomb explosion of N2, under the impact of highly-charged ions at intermediate velocities

“…The resulting transient molecular ion eventually decays into the constituent atomic and (or) molecular ions via Coulomb explosion. The degree of ionization and the KER distributions, in general, are expected to depend on the charge state (q p ) and velocity (v p ) of the projectile ions [16,17,19,37,38].…”

“…The study of multiply-charged molecular ions has evolved over several decades, starting from the initial measurements of the appearance energies and abundances of these ions [1] to the stability and fragmentation dynamics [2,3]. With the advent of fragment ion momentum imaging techniques such as recoil ion momentum spectroscopy [4,5], a large volume of work has been reported in the literature pertaining to the study of the decay dynamics of the molecular ions which are formed in interactions with photons [6][7][8][9], electrons [10][11][12][13][14] and heavy ions [15][16][17][18][19][20][21][22]. In particular, the multiple ionization and subsequent dissociation of small molecules or molecule-like species produced in highly-charged ion impact is a subject of current [17][18][19][28][29][30][31][32].…”

“…With the advent of fragment ion momentum imaging techniques such as recoil ion momentum spectroscopy [4,5], a large volume of work has been reported in the literature pertaining to the study of the decay dynamics of the molecular ions which are formed in interactions with photons [6][7][8][9], electrons [10][11][12][13][14] and heavy ions [15][16][17][18][19][20][21][22]. In particular, the multiple ionization and subsequent dissociation of small molecules or molecule-like species produced in highly-charged ion impact is a subject of current [17][18][19][28][29][30][31][32]. The KER distributions of fragmenting N 2 q+ ions have been studied extensively over recent decades and have also been a benchmark system to calibrate the experimental setups (N 2 2+ KER distribution).…”