2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/114374We derive an analytical formula for the ionization rate of neutral atoms and molecules in a strong monochromatic field. Our model is based on the strong-field approximation with transition amplitudes calculated by an extended saddle point method. We show that the present two-term saddle point method reproduces even complicated structures in angular resolved photo electron spectra.Atomic Physicstext