The role of the Debye screening of circular Rydberg states of hydrogenic systems in collinear electric and magnetic fields of arbitrary strengths

We consider classical circular Rydberg states of a hydrogenic atom/ion under collinear electric and magnetic fields of arbitrary strengths, the entire system being immersed into a plasma with the Debye screening. In this way we add a “new dimension” to the results of the previous paper of one of us, where the screening was not taken into account. We show in detail how the screening decreases the value of the critical electric field required for the ionization at different values of the magnetic field. Our results should have a fundamental importance because hydrogenic atoms/ions under external fields remain a test-bench for atomic physics. Also our results could motivate experiments on the magnetic control of the “continuum lowering” in cold Rydberg plasmas, this being of practical importance.