Lorentz Dispersion Law from classical Hydrogen electron orbits in AC electric field via geometric algebra

We studied the orbit of an electron revolving around an infinitely massive nucleus of a large classical Hydrogen atom subject to an AC electric field oscillating perpendicular to the electronu0027s circular orbit. Using perturbation theory in geometric algebra, we show that the equation of motion of the electron perpendicular to the unperturbed orbital plane satisfies a forced simple harmonic oscillator equation found in Lorentz dispersion law in Optics. We show that even though we did not introduce a damping term, the initial orbital position and velocity of the electron results to a solution whose absorbed energies are finite at the dominant resonant frequency $omega=omega_0$; the electron slowly increases its amplitude of oscillation until it becomes ionized. We computed the average power absorbed by the electron both at the perturbing frequency and at the electronu0027s orbital frequency. We graphed the trace of the angular momentum vector at different frequencies. We showed that at different perturbing frequencies, the angular momentum vector traces epicyclical patterns.