Vorschau

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Abstract

The direct measurement of the gravitational acceleration of antimatter in the earth's field, which represents a test of the weak equivalence principle, is in the focus of several ongoing experimental attempts. This thesis investigates tools and techniques known from the field of atom optics that can be utilised for such a measurement with antihydrogen atoms as envisioned by the AEgIS collaboration. A first experimental step is presented, in which a detection due to an electromagnetic force acting on antiprotons is measured with a moiré deflectometer. This device, which can be described with classical particle trajectories, consists of two gratings and a spatially resolving detector. Key elements of this measurement are the use of an emulsion detector with high spatial resolution and an absolute reference technique based on an interferometric fringe pattern of light, which is not deflected by forces. For future realisations, a new detection and evaluation scheme to measure gravity based on a three-grating system enclosed by a vertex-reconstructing detector is discussed. This allows the use of a grating periodicity that is smaller than the resolution of the detector while making efficient use of the particle flux. Smaller periodicities are favourable to increase the inertial sensitivity of the measurement apparatus but require to take effects of diffraction into account. To explore this near-field regime with antimatter, a Talbot-Lau interferometer for antiprotons is proposed and its possible experimental implementation is discussed.