Analysis of initial energies of fragments produced by 65-keV proton-molecule collisions using a time-of-flight mass spectrometer

Electron impact dissociative ionization of the CH2F2molecule: cross sections, appearance potentials, nascent kinetic energy distributions and dissociation pathways

“…The TOF-MS band profile depends mainly on both the nascent ion positions with respect to the extraction plate (Wiley and McLaren 1955) and their kinetic energies (Franklin et al 1967, Schäfer et al 1991. Indeed, and as an example, figure 2 shows the modelled Ar + (40 amu) and C + (12 amu) ion trajectories TOFs in our system as a function of the ion initial distance to the extraction plate (s, in cm); the bold curves correspond to zero kinetic energy ions and the others to ions with velocities directed to (full curves) and from (broken curves) the MCP detector, at 0.1 eV kinetic energy steps.…”

“…Nascent kinetic energy distributions, n(U (t)), are readily worked out from the TOF band profiles, f (t), according to the relationship (Schäfer et al 1991):…”

Fragmentation of CO caused by fast F4+ impact

“…This distribution is varied until good agreement between the simulated spectrum and the experimental one is reached. Another method was suggested recently by Sch/ifer et al 1 for the evaluation of the kinetic energy distribution of single fragments from their TOF spectra. In this method the kinetic energy distribution is related to the time derivative of the TOF spectrum.…”

Electron-impact dissociative ionization of CClF3 and CCl3F

“…The latter induces an asymmetry in the TOF band wing associated with the short times; however, the wing related to the higher time-of-flight is unaffected and hence used to derive the ion KED. As reported elsewhere [3,23] the KED is computed as the first derivative of the unaffected band profile wing times 2m/(qE) 2 , where E is the electric field of the ionization region and m and q the mass and charge of the ions.…”