Experimental confirmation of circular Rydberg states with projectile-like ions

Abstract

Using projectile-like ions instead of projectile ions in a beam–foil source, we have reconfirmed the formation of circular Rydberg states. The projectile-like 6028Ni and 6329Cu ions have been produced by a 5626Fe ion beam and 6230Zn ions by a 5828Ni ion beam, at beam energies above the Coulomb barrier, bombarding a thin carbon foil. Time-resolved x-ray transitions of these projectile-like ions attain their maximum intensities at different delays. Such delays are attributed to successive cascading through yrast transitions from the circular Rydberg levels, which find important implications in understanding the origin of radio recombination lines from interstellar space.