[Step back on the COMPLETE sequential path to the covering module (link type: SQ-BACK/is part of/is generalised in; target: A05-m4bi2)] [Next step on the COMPLETE sequential path to more treated results (link type: SQ-NEXT; target: A05-m5)]
[Step back on the ESSAY-TYPE sequential path to the module Treated results (link type: ESSAY-BACK/seq-back; target: A05-m4bi1)] [Next step on the ESSAY-TYPE sequential path to more treated results  (link type: ESSAY-NEXT/sq-next; target: A05-m4bii)]
[Show the characterisation of the module]
[Show the navigation menu of the module]
[Show the Map of contents]
[Legenda]


[Contents
of the thesis]
[Comments]
































































[Step back on the COMPLETE sequential path to the covering module (link type: SQ-BACK/is part of/is generalised in; target: A05-m4bi2)] [Next step on the COMPLETE sequential path to more treated results (link type: SQ-NEXT; target: A05-m5)]
[Step back on the ESSAY-TYPE sequential path to the module Treated results (link type: ESSAY-BACK/seq-back; target: A05-m4bi1)] [Next step on the ESSAY-TYPE sequential path to more treated results  (link type: ESSAY-NEXT/sq-next; target: A05-m4bii)]
[Show the characterisation of the module]
[Show the navigation menu of the module]
[Show the Map of contents]
[Legenda]


[Contents
of the thesis]
[Comments]

Treated results = A05-m4bii

The ionic potential for the system K + Br2 K+ + Br2- is given by a Rittner potential of the form [The formula is obtained from Rittner's article (link type: INPUT FROM; target: R(A05)4-m*]
Uion(R) = $\displaystyle -\frac{e^2}{R}-\frac{e^2(\alpha_{\Na^+}+\alpha_{\I^-})}{2R^4}$  
    $\displaystyle -\frac{2e^2\alpha_{\Na^+}\alpha_{\I^-}}{R^7}-\frac{C_\ion}{R^6}$  
    $\displaystyle +A_\ion\, \er^{-R/\rho_\ion}+\Delta E.$ (E1)
(a coulombic term, a screened polarization term, dipole-dipole interaction and the endothermicity ${\Delta }E$) and the covalent potential is given by a Van der Waals term and the repulsive term:
\begin{displaymath}U_\cov(R)=-\frac{C_\cov}{R^6}+A_\cov\,\er^{-R/\rho_\cov} (E2)
with the following values [These values are determined in the Quantitative interpretation (link type: INPUT FROM; target: A05-m5bi]:
\begin{eqnarray*}{\Delta} E&=&3.1\ \mathrm{eV},\\
\alpha _{\zs\Br_2^-}&=&150\ ...
...10^5\ \mathrm{eV},\\
H_{12}&=&4.5\times 10^{-2}\ \mathrm{eV},
\end{eqnarray*}
and the values
\begin{eqnarray*}\alpha_{\zs\K^+} &=& 0.94\ \AA^3\quad (\mbox{\link{[(link type:...
...box{arbitrary})\\
\quad a &=& 5\ \AA,\quad (\mbox{arbitrary})
\end{eqnarray*}
The resulting potential is presented in figure A05-m4bii-F1.

[to the FULL figure] Figure A05-m4bii-F1: K + BR2 ionic and covalent potential.

For a system with the potential given above, the deflection function turns out to be closed. Figure A05-m4bii-F1 represents the deflection curves for chemi-ionization scattering of K + Br2 (CM system).

The full curves represent the classically calculated scattering angle for ``ionic'' and ``covalent'' scattering at colliding energies of 10.35 and 6.9 eV, determined using a simple classical model and measurements of the differential cross section in a molecular beam experiment. The dashed curves show the ``pure inelastic'' scattering-angle contribution to the full-line curves.

[to the FULL figure] Figure A05-m4bii-F2: K + BR2, deflection curves for chemi-ionization scattering (CM system. [(link type: `input from'; target:  interpretation m5bi]

The differential cross section calculated based on the deflection function given above has the following shape: Figure A05-m4bii-F3 represents the classically calculated determined chemi-ionization differential cross section of K + Br2 (CM system) at colliding energies of 6.9 and 10.35 eV and convoluted with the energy spread of the velocity selector.

[to the FULL figure] Figure A05-m4bii-F3: K + BR2, classically calculated chemi-ionization differential cross section (CM system) at colliding energies of 6.9 eV and 10.35 eV. [The figure is input from the Quantitative interpretation (link type: INPUT FROM; target: A05-m5bii]

For both energies equal units have been used on the ordinate. The dotted lines indicate the $\rho $ dependence of the slope steepness for ``covalent'' scattering. At Ei= 10.35 eV and different values of the polarizability $\alpha _{\zs\Br_2^-}$, and the ionic-well minimum $\varepsilon $ the positions of the scattering angle for b=Rcscattering respectively the classical rainbow angle have been indicated along the abscissa. The values used in the calculations have been underlined.