Stark Effect and Series Limits

THE treatments of the Stark effect found in the literature concern themselves chiefly with the behaviour of atoms in the lower quantum states, a problem to which the theory of perturbations can be applied. Consideration of the effect of the external electric field on highly excited atoms necessitates the discussion of the complete equations, in particular with regard to the existence of conditionally periodic orbits. The investigation which we have carried out gives a negative upper limit for the energy of quantised orbits in a hydrogen-like atom, and shows that there exist various types of unquantised orbits which have negative energies.