title: Deceleration, precooling, and multi-pass stopping of highly charged ions in Be⁺ Coulomb crystals.
abstract: Preparing highly charged ions (HCIs) in a cold and strongly localized state is of particular interest for frequency metrology and tests of possible spatial and temporal variations of the fine structure constant. Our versatile preparation technique is based on the generic modular combination of a pulsed ion source with a cryogenic linear Paul trap. Both instruments are connected by a compact beamline with deceleration and precooling properties. We present its design and commissioning experiments regarding these two functionalities. A pulsed buncher tube allows for the deceleration and longitudinal phase-space compression of the ion pulses. External injection of slow HCIs, specifically Ar(13+), into the linear Paul trap and their subsequent retrapping in the absence of sympathetic cooling is demonstrated. The latter proved to be a necessary prerequisite for the multi-pass stopping of HCIs in continuously laser-cooled Be(+) Coulomb crystals.
authors.affiliation: Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Schmöger
authors.affiliation: Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Schwarz
authors.affiliation: Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany.
authors.forename: T M
authors.initials: TM
authors.lastname: Baumann
authors.affiliation: Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany.
authors.forename: O O
authors.initials: OO
authors.lastname: Versolato
authors.affiliation: Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Piest
authors.affiliation: Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Pfeifer
authors.affiliation: Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Ullrich
authors.affiliation: Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany.
authors.forename: P O
authors.initials: PO
authors.lastname: Schmidt
authors.affiliation: Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany.
authors.forename: J R Crespo
authors.initials: JR
authors.lastname: López-Urrutia