K. Wien et al., LINE SHIFTS IN MASS-SPECTRA OF SECONDARY IONS EJECTED FROM SOLIDS BY MEV-ION IMPACT, Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms, 100(2-3), 1995, pp. 322-330
Emission of hydrogen ions has been used to investigate the charging of
the nuclear track being produced by fission fragments in organic soli
ds. The question of interest is, if in insulating material the lifetim
e of ionisation along the nuclear track is sufficiently long to allow
atomic motion driven by Coulomb repulsion of neighbouring ionized atom
s. It is shown in this article that the hydrogen ions experience the p
otential produced by the ionized track core, but weaker than Auger ele
ctrons (see Schiwietz et al., Phys. Rev. Lett. 69 (1992) 628). In orde
r to determine the mean initial energy of emission, we measured the ti
me-of-flight distributions of secondary ions by means of a linear TOF
instrument being equipped with 2 acceleration grids and converted them
into axial energy distributions. Monte Carlo simulations were used to
simulate the time distributions and to estimate the mean charge along
the nuclear track causing the observed line shifts.