title: Electrostatically Guided Rydberg Positronium.
abstract: We report experiments in which positronium (Ps) atoms were guided using inhomogeneous electric fields. Ps atoms in Rydberg-Stark states with principal quantum number n=10 and electric dipole moments up to 610 D were prepared via two-color two-photon optical excitation in the presence of a 670  V cm^{-1} electric field. The Ps atoms were created at the entrance of a 0.4 m long electrostatic quadrupole guide, and were detected at the end of the guide via annihilation gamma radiation. When the lasers were tuned to excite low-field-seeking Stark states, a fivefold increase in the number of atoms reaching the end of the guide was observed, whereas no signal was detected when high-field-seeking states were produced. The data are consistent with the calculated geometrical guide acceptance.
authors: Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom.
authors: A
authors: A
authors: Deller
authors: Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom.
authors: A M
authors: AM
authors: Alonso
authors: Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom.
authors: B S
authors: BS
authors: Cooper
authors: Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom.
authors: S D
authors: SD
authors: Hogan
authors: Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom.
authors: D B
authors: DB
authors: Cassidy