For Rydberg atoms in an electric field F = 19 V/cm, the escape time that electrons take to strike the detector is plotted as a function of the initial launch angle at the same scaled energy ε = −1.3. (a) The escape time plot of the helium atom, chaotic region A is the typical fractal self-similarity region. (b) The escape time plot of the lithium atom, chaotic region B is the typical fractal self-similarity region. The dotted rectangles exhibit the same rhythm endings.