Eur. Phys. J. D (2014) 68: 41
https://doi.org/10.1140/epjd/e2013-40690-3

Regular Article

AEgIS experiment: Towards antihydrogen beam production for antimatter gravity measurements^*

¹ Stefan-Meyer-Institut für subatomare Physik, Boltzmanngasse 3, 1090 Vienna, Austria
² Politecnico di Milano, LNESS and Dept of Physics, Via Anzani 42, 22100 Como, Italy
³ Istituto Nazionale di Fisica Nucleare, Sez. di Milano, Via Celoria 16, 20133 Milano, Italy
⁴ Albert Einstein Center for Fundamental Physics, Laboratory for High Energy Physics, University of Bern, 3012 Bern, Switzerland
⁵ Institute for Nuclear Research of the Russian Academy of Sciences, 117312 Moscow, Russia
⁶ University of Brescia, Dept of Mech. and Indust. Engineering, Via Branze 38, 25133 Brescia, Italy
⁷ Istituto Nazionale di Fisica Nucleare, Sez. di Pavia, Via Agostino Bassi 6, 27100 Pavia, Italy
⁸ University of Heidelberg, Kirchhoff Institute for Physics, Im Neuenheimer Feld 227, 69120 Heidelberg, Germany
⁹ Department of Physics, University of Trento and INFN TIFPA, Via Sommarive 14, 38123 Povo, Trento, Italy
¹⁰ European Organisation for Nuclear Research, Physics Department, 1211 Genève 23, Switzerland
¹¹ Laboratoire Aimé Cotton, CNRS, Université Paris Sud, ENS Cachan, Bâtiment 505, Campus d’Orsay, 91405 Orsay Cedex, France
¹² University of Zurich, Physics Institute, Winterthurerstrasse 190, 8057 Zürich, Switzerland
¹³ University of Milano, Dept of Physics, Via Celoria 16, 20133 Milano, Italy
¹⁴ Politecnico di Milano, Dept of Aerospace Sci. and Tech., Via La Masa 34, 20156 Milano, Italy
¹⁵ Istituto Nazionale di Fisica Nucleare, Sez. di Genova, Via Dodecaneso 33, 16146 Genova, Italy
¹⁶ University of Bergen, Institute of Physics and Technology, Alleegaten 55, 5007 Bergen, Norway
¹⁷ University College London, Dept of Physics and Astronomy, Gower Street, London WC1E 6BT, UK
¹⁸ Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, 69117 Heidelberg, Germany
¹⁹ University of Genoa, Dept of Physics, Via Dodecaneso 33, 16146 Genova, Italy
²⁰ Joint Institute for Nuclear Research, 141980 Dubna, Russia
²¹ ETH Zurich, Laboratory for Physical Chemistry, 8093 Zürich, Switzerland
²² Istituto Nazionale di Fisica Nucleare, Sez. di Padova, Via Marzolo 8, 35131 Padova, Italy
²³ Claude Bernard University Lyon 1, Institut de Physique Nucléaire de Lyon, 4 rue Enrico Fermi, 69622 Villeurbanne, France
²⁴ Czech Technical University in Prague, FNSPE, Bøehová 7, 11519 Praha 1, Czech Republic
²⁵ University of Bologna, Dept of Physics, Via Irnerio 46, 40126 Bologna, Italy
²⁶ University of Pavia, Dept of Nuclear and Theoretical Physics, Via Bassi 6, 27100 Pavia, Italy
²⁷ University of Oslo, Dept of Physics, Sem Sælands vei 24, 0371 Oslo, Norway
²⁸ University of Napoli Federico II, Department of Physics, Via Cinthia, 80126 Napoli, Italy

^a e-mail: mariazzi@science.unitn.it

Received: 4 November 2013
Received in final form: 17 December 2013
Published online: 4 March 2014

Abstract

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 moiré 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 10³ 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.