Abstrakt
Collisions of keV atomic cations (He+, Ne+, Ar+, Kr+, Xe+, F+, Cl+, Br+, I+, Se+, Te+, Sb+, and Fe+) with neutral hydrocarbon molecules (methane, ethane, propane, and benzene) were measured using a modified sector type mass spectrometer. The atomic cations were produced in an electron ionization ion source, accelerated and mass selected by a magnetic sector.
The beam of cations was subsequently guided into a collision chamber filled with the neutral hydrocarbon molecules. Secondary ions stemming from the ion/molecule interactions were analyzed by a quadrupole mass analyzer placed perpendicularly to the ion beam.
Results presented in this paper show strong dependence of product ion formation and relative fragmentation yield (expressed as a Sigma[F+(i)]/(Sigma[F+(i)] + [M+]) ratio) on recombination energy of projectile ions. The influence of center-of-mass collision energy, as well as kinetic energy of the projectile, on secondary ion formation are also explored and discussed.