The impact ionization rate and its orientation dependence in k space is calculated for ZnS. The numerical results indicate a strong correlation to the band structure. The use of a q-dependent screening function for the Coulomb interaction between conduction and valence electrons is found to be essential. A simple fit formula is presented for easy calculation of the energy dependent transition r...

Normalized values of cross sections for the production of ions by electron impact on N20 and NO have been obtained by utilizing the relative flow technique. The accurately known values of cross sections for the production of singly charged ions of rare gases from the parent atoms have been used for the normalization. Cross sections for the generation of fragment ions have been measured for the ...

We study electron-impact single-ionization cross-sections for all levels of the ground configuration Ar2+ ion using distorted wave approximation. investigate influences direct ionization and excitation-autoionization processes on total cross sections. used corrected energies Ar3+ so that threshold corresponds to value recommended by National Institute Standards Technology (NIST). Radiative damp...

We present ionization cross-sections of collisions between electrons and carbon atoms using the classical trajectory Monte Carlo method. Total are benchmarked against reported experimental data predictions numerically intensive theoretical methods as well pioneering calculations for this collision system. At impact energies greater than about 100 eV, results in very good agreement with generali...

We describe a novel ion source for analytical mass spectrometry based on femtosecond laser ionization at pressures at and above atmospheric and characterize its performance when coupled to a tandem quadrupole/time-of-flight mass spectrometer. We assess source saturation limits, ionization and sampling efficiencies, the effective ionization volume, and limits of detection. We demonstrate 100% ef...