Hamburg 2009 – scientific programme

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A: Fachverband Atomphysik

A 3: Precision Spectroscopy of Atoms and Ions I

A 3.2: Fachvortrag

Monday, March 2, 2009, 14:30–15:00, VMP 6 HS-B

Proposed gravity measurement with antihydrogen — •Carlo Canali, Arne Fischer, Ulrich Warring, and Alban Kellerbauer — Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany

The gravitational interaction between matter and antimatter has never been tested experimentally. The AEGIS experiment (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) intends to measure for the first time the gravitational acceleration of antihydrogen. H will be obtained through a charge exchange process between Rydberg positronium atoms and antiprotons. The antiprotons will be delivered by the CERN AD (Antiproton Decelerator). After being captured and confined inside a cylindrical Penning trap, they will be cooled down to ≈ 100 mK. At the same time, positronium will be produced by bombardment of a nanoporous insulator material with positrons. A double laser pulse will excite the positronium to a Rydberg state immediately before the interaction with the antiprotons, such as to increase the cross-section for the charge exchange process. The produced antihydrogen atoms will be accelerated to form a horizontal beam and projected through a Moiré deflectometer with a velocity of a few 100 m/s along a path of about 1 m length. The deflectometer consists of two gratings and a position-sensitive detector able to measure the vertical displacement and the time of flight of H atoms. With this setup an initial precision on the measurement of g(H) of 1% is expected.