Production of multiply charged molecular ions (N2 12+-N2 14+) and multiply charged atomic ions (N6+, N7+) in energetic, heavy-ion impact on N2 molecules.

Abstract

Multiply charged atomic recoil ions up to ${\mathrm{N}}^{6+}$, along with a weak trace of ${\mathrm{N}}^{7+}$ ions, have been observed in 1.05--MeV/amu ${\mathrm{Ar}}^{12+}$-ion impact on molecular targets (${\mathrm{N}}_{2}$). A shift of the peak positions for these multiply charged atomic ions (${\mathrm{N}}^{\mathrm{j}+}$) toward the high-energy side in charge-energy spectra, compared with those for recoil ions from single-atom targets such as Ar, strongly suggests that these recoil ions (${\mathrm{N}}^{\mathrm{j}+}$) have fairly large initial kinetic energies due to the Coulomb explosion of multiply charged molecular ions produced in the impact of highly charged projectiles. It is believed, therefore, that those multiply charged atomic ions, for example, ${\mathrm{N}}^{6+}$ ions, originate from multiply charged molecular ions, for example, ${\mathrm{N}}_{2}$${\mathrm{}}^{11+}$, ${\mathrm{N}}_{2}$${\mathrm{}}^{12+}$, or ${\mathrm{N}}_{2}$${\mathrm{}}^{13+}$ ions, which dissociate into two atomic ions.