title: Low-current, vertical blowup in a stored laser-cooled ion beam.
abstract: Using a novel technique for real-time transverse beam profile diagnostics of a stored ion beam, we have observed the transverse size of a stored laser-cooled ion beam. Earlier we observed that the density of the beam is independent of the beam current. At very low currents, we observe an abrupt change in this behavior: The vertical beam size increases suddenly by about an order of magnitude. This observation implies a sudden change in the indirect vertical cooling mediated by intrabeam scattering. Our results have serious implications for the ultimate beam quality attainable by laser cooling.
authors.affiliation: CERN, Geneva, Switzerland.
authors.forename: N
authors.initials: N
authors.lastname: Madsen
authors.forename: P
authors.initials: P
authors.lastname: Bowe
authors.forename: J S
authors.initials: JS
authors.lastname: Nielsen
authors.forename: L E
authors.initials: LE
authors.lastname: Siegfried
authors.forename: J S
authors.initials: JS
authors.lastname: Hangst