Excitation and photoionization processes involving the bound ns electrons

Photoionization pathways and free electrons in UV-MALDI.

The recently developed model for primary and secondary UV-MALDI ion formation (Knochenmuss, R. J. Mass Spectrom. 2002, 37, 867-877. Knochenmuss, R. Anal. Chem. 2003, 75, 2199.) is applied to questions regarding photoionization pathways and electron versus negative ion production. Two-photon ionization of the matrix in direct contact with analyte is possible under some circumstances (Kinsel, G.;...

EEDF MEASUREMENTS AND EXCITATION PROCESSES IN THE VICINITY OF A HELIUM DISCHARGE CONSTRICTION

Axial distributions of plasma and floating potentials, electron number density and the electron energy distribution function (EEDF) have been measured in the double layer (DL) region of an He discharge constriction. Excitation processes in the constriction region are studied. Using a linearization method for the nonstationary balance equations and choosing appropriate discharge conditions, ...

Excitation of the symmetry forbidden bending mode in molecular photoionization

We present results on the energy dependence of the vibrational branching ratio for the bending mode in CO2 3su 21 photoionization. Specifically, we determine the v5(0,1,0)/v5(0,0,0) intensity ratio by detecting dispersed fluorescence from the electronically excited photoions. The results exhibit large deviations over a very wide energy range, 18,hnexc,190 eV. Production of the v5(0,1,0) level o...

Electromagnetic radiation from bound electrons

Rotational excitation of H2O by cold electrons.

Experimental data are presented for the scattering of electrons by H2O between 17 and 250 meV impact energy. These results are used in conjunction with a generally applicable method, based on a quantum defect theory approach to electron-polar molecule collisions, to derive the first set of data for state-to-state rotationally inelastic scattering cross sections based on experimental values.