Example: electron elastic scattering on molecules with large dipole moment

In the case of molecule with large permanent dipole momentum the electron-target interaction is described by charge-dipole interaction potential. In this case the quantum mechanical treatment in the first Born approximation gives the simple formula for electron-molecule transport cross section. According to this formula the cross section is inversely proportional to the electron energy with the coefficient depending upon the molecular dipole moment. Figure below demonstrates the results of such calculation and experimental data for electron scattering on KI molecule. Alkali-halide molecules have high dipole moment therefore approach described above is applicable for the calculation of elastic cross section.