Minima of Generalized Oscillator Strengths for Electron-Impact Excitation of the6P11and6p′P13States of Hg

Differential cross sections for excitation of the $6{}_{}{}^1{}_{}{}^{}P_1^{}{}_{}{}^{}$ and $6p^{\prime }{}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}$ states of mercury have been measured at angles where minima of the generalized oscillator strengths could be expected. The minima appeared for both channels. Contrary to the results of the first Born approximation, their position depends not only on the momentum transfer but also on the primary energy. The confidence of some authors in the reliability of the Born approximation for inelastic scattering is not justified.