Electrostatic analyzer energy dispersion

The TOF is the most widely used analyzer for SIMS experiments. The TOF is based on the measurement of the time elapsed between the impact of the pulsed primary beam on the sample surface and the detection of the emitted secondary ions by the ion detector. The flight time of ions with different m/z (typically larger than 1 ps) is proportional to the ratio itself and is used to analyze the different ions. TOF analyzers are often used in conjunction with pulsed primary ion sources because the latter offer the possibility to synchronize the ion detection with the primary ion source pulse frequency. Reflectron TOF analyzers compensate for the secondary ion kinetic energy dispersion by using an electrostatic mirror that gradually reflects ions with the same m/z but with different kinetic energy. 

Figure 3.2.2.S Cross-sectional view of the Scienta R4000 hemispherical electrostatic energy analyzer equipped with a two-dimensional detector for parallel detection in energy and emission angle. Typical electron trajectories are shown for two different energies, starting at the sample surface and indicating both the focusing by the electrostatic lens and the hemispherical analyzer, as well as the energy dispersion on the detector plane. A similar dispersion takes place...

In order to analyze the interaction energy component, the symmetry-adapted perturbation theory (SAPT) [12] calculations were performed. SAPT have been used to analyze the interaction energies in terms of electrostatic, induction, dispersion, and exchange interaction components. The SAPT interaction energy (Dint) has been analyzed up to the second-order symmetry adapted perturbation theory the electrostatic energy (Dekt) consisting of and... 

Xo-type interactions and analyzed their energy components (electrostatic, induction, dispersion, and exchange repulsion energies). In addition, by studying the corresponding water-Y complexes, we compared them with phenol-Y complexes. 

The electrostatic components of disjoining pressure and free energy of interaction in the film, given by eqs. (VII.21) and (VII.22), are positive, i.e. represent repulsion. These quantities may be compared with corresponding molecular components that are negative and describe attraction. This allows one to analyze according to the DLVO theory the stability of thin films, and consequently of disperse systems stabilized by adsorption layers. Carrying out summation of eqs. (VII.21) and (VII.22) with expressions (VII.9) and (VII. 10) one obtains ... 

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