2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/83570The electric field in mm-sized clouds of cold Rb^+-ions is measured using the Stark effect of Rydberg atoms embedded in the ion clouds. The ion clouds are produced by UV photoionization of laser-cooled rubidium atoms in a magneto-optic trap. In very dense ion clouds, the Rydberg atom excitation spectra reflect the presence of a neutral plasma core and a positively charged ion shell.Atomic PhysicsPlasma Physicstext