AEgIS Experiment: Towards Antihydrogen Beam Production for Antimatter Gravity Measurements

Mariazzi, S.; Aghion, Stefano; Amsler, C.; Ariga, A.; Ariga, T.; Belov, A. S.; Bonomi, G.; Braunig, P.; Brusa, R. S.; Bremer, J.; Cabaret, L.; Canali, C.; Caravita, R.; Castelli, F.; Cerchiari, G.; Cialdi, S.; Comparat, D.; Consolati, Giovanni; Dassa, L.; Derking, J. H.; Di Domizio, S.; Di Noto, L.; Doser, M.; Dudarev, A.; Ereditato, A.; Ferragut, RAFAEL OMAR; Fontana, A.; Genova, P.; Giammarchi, M.; Gligorova, A.; Gninenko, S. N.; Hogan, S. D.; Haider, S.; Jordan, E.; Jorgensen, L. V.; Kaltenbacher, T.; Kawada, J.; Kellerbauer, A.; Kimura, M.; Knecht, A.; Krasnicky, D.; Lagomarsino, V.; Lehner, S.; Malbrunot, C.; Matveev, V. A.; Merkt, F.; Moia, Fabio; Nebbia, G.; Nedelec, P.; Oberthaler, M. K.; Pacifico, N.; Petracek, V.; Pistillo, C.; Prelz, F.; Prevedelli, M.; Regenfus, C.; Riccardi, C.; Rohne, O.; Rotondi, A.; Sandaker, H.; Scampoli, P.; Storey, J.; Subieta Vasquez, M. A.; Spacek, M.; Testera, G.; Vaccarone, R.; Villa, F.; Widmann, E.; Zavatarelli, S.; Zmeskal, J.

doi:10.1140/epjd/e2013-40690-3

AEgIS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) is an experiment that aims to perform the first direct measurement of the gravitational acceleration g of antihydrogen in the Earth's field. A cold antihydrogen beam will be produced by charge exchange reaction between cold antiprotons and positronium excited in Rydberg states. Rydberg positronium (with quantum number n between 20 and 30) will be produced by a two steps laser excitation. The antihydrogen beam, after being accelerated by Stark effect, will fly through the gratings of a moir, deflectometer. The deflection of the horizontal beam due to its free fall will be measured by a position sensitive detector. It is estimated that the detection of about 10(3) antihydrogen atoms is required to determine the gravitational acceleration with a precision of 1%. In this report an overview of the AEgIS experiment is presented and its current status is described. Details on the production of slow positronium and its excitation with lasers are discussed.