Photoionization artifacts from model Rydberg atoms

Assuming the initial population in the hydrogenic 50s state, we simulate Ry dberg-state redistribution and photoionization by a nonresonant optical-fre quency pulse versus the number of different n manifolds included. The inclu sion of additional n manifolds, around the n = 50 manifold distinguished by the initial-state choice, is shown to invalidate the photoionization predi ctions based on the single-n manifold approximation. The calculations are p erformed assuming a linearly polarized, 620 nm. pulse, turned on and off su ddenly, of ten-optical-period duration and peak intensity 10(9) W cm(-2) en suring effective transient mixing of both-parity Rydberg states around n = 50.