Charge exchange differential

From the Mulliken population, we calculate the charge exchange differential cross section. For a more complex system, in Fig. 6, the preliminary results for the direct and charge transfer differential cross section are shown for protons colliding with water at 5.0 keV as obtained by the Mulliken population analysis combined with the Schiff approximation [equation (23)]. Also for comparison we present the experimental results from Lindsay et al. [29]. 

Fig. 6. Preliminary results for the direct and charge exchange differential cross section for — H2O for at 5.0 keV. The experimental data for the differential...

It is also possible to produce He(23S) atoms by the charge exchange of He+ ions in cesium-vapor.93 This technique has been used extensively by the Stanford Research Institute (SRI) group to measure differential cross sections at higher energies (5 to 10 eV). Some of the data94 in reduced units... 

Figure 19. Reduced-variable plot of He (23S) + He differential cross sections, obtained with charge-exchange He source.

Simonsick WJJ, Hites RA. 1985. Charge exchange chemical ionization mass spectrometry A tool for PAH isomer differentiation. In Cooke M, Dennis AJ, eds. Polynuclear aromatic hydrocarbons Mechanisms, methods and metabolism. Columbus, OH Battelle Press, 1227-1237. 

Not many results have been reported so far on atom-atom charge exchange collisions in the eV range (see Tables IV and VI), but those which have been obtained are extremely interesting. Total cross sections have been measured for Cs on O and Na, Li on I, whereas differential cross sections only have been reported for Na + I. 

Keough, T. Mihelich, E.D. Eickhoff, D.J. Differentiation of Monoepoxide Isomers of Polyunsaturated Fatty Acids and Fatty Acid Esters hy Low-Energy Charge Exchange Mass Spectronretry. Anal. Chem. 1984,56,1849-1852. 

The ability of living organisms to differentiate between the chemically similar sodium and potassium ions must depend upon some difference between these two ions in aqueous solution. Essentially, this difference is one of size of the hydrated ions, which in turn means a difference in the force of electrostatic (coulombic) attraction between the hydrated cation and a negatively-charged site in the cell membrane thus a site may be able to accept the smaller ion Na (aq) and reject the larger K (aq). This same mechanism of selectivity operates in other ion-selection processes, notably in ion-exchange resins. 

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