AEGIS at CERN: Measuring Antihydrogen Fall

The main goal of the AEGIS experiment at the CERN Antiproton Decelerator is the test of fundamental laws such as the Weak Equivalence Principle (WEP) and CPT symmetry. In the first phase of AEGIS, a beam of antihydrogen will be formed whose fall in the gravitational field is measured in a Moire' deflectometer; this will constitute the first test of the WEP with antimatter.Comment: Presented at the Fifth Meeting on CPT and Lorentz Symmetry, Bloomington, Indiana, June 28-July 2, 201

Proposed antimatter gravity measurement with an antihydrogen beam

The principle of the equivalence of gravitational and inertial mass is one of the cornerstones of general relativity. Considerable efforts have been made and are still being made to verify its validity. A quantum-mechanical formulation of gravity allows for non-Newtonian contributions to the force which might lead to a difference in the gravitational force on matter and antimatter. While it is widely expected that the gravitational interaction of matter and of antimatter should be identical, this assertion has never been tested experimentally. With the production of large amounts of cold antihydrogen at the CERN Antiproton Decelerator, such a test with neutral antimatter atoms has now become feasible. For this purpose, we have proposed to set up the AEGIS experiment at CERN/AD, whose primary goal will be the direct measurement of the Earth's gravitational acceleration on antihydrogen with a classical Moiré deflectometer. © 2007 Elsevier B.V. All rights reserved

Antihydrogen physics: Gravitation and spectroscopy in AEgIS

AEgIS (Antimatter experiment: gravity, interferometry, spectroscopy) is an experiment approved by CERN with the goal of studying antihydrogen physics. In AEgIS, antihydrogen will be produced by charge exchange reactions of cold antiprotons with positronium atoms excited in a Rydberg state (n>20). In the first phase of the experiment, controlled acceleration by an electric field gradient (Stark effect) and subsequent measurement of free fall in a Moiré deflectometer will allow a test of the weak equivalence principle. In a second phase, the antihydrogen will be slowed, confined, and laser-cooled to perform CPT studies and detailed spectroscopy. In the present work, after a general description of the experiment, the present status of advancement will be reviewed, with special attention to the production and excitation of positronium atoms

The AEGIS experiment (Antimatter experiment: Gravity, interferometry, spectroscopy)

The primary goal of the AEgIS experiment is to measure the gravitational acceleration of antihydrogen. Once performed this could be the first direct test of the gravitational interaction between matter and antimatter. The measurement will be performed producing a horizontal beam of anti hydrogen and measuring its vertical displacement over a length of about one meter. To do this the produced horizontal beam will travel along a moire deflectometer followed by a position sensitive detector. An initial precision on the measurement of g of 1 % is expected: This will pave the way for future highprecision measurements. © 2010 by World Scientific Publishing Co. Pte. Ltd

Antihydrogen physics: gravitation and spectroscopy in AEgISThis paper was presented at the International Conference on Precision Physics of Simple Atomic Systems, held at École de Physique, les Houches, France, 30 May – 4 June, 2010.

AEgIS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) is an experiment approved by CERN with the goal of studying antihydrogen physics. In AEgIS, antihydrogen will be produced by charge exchange reactions of cold antiprotons with positronium atoms excited in a Rydberg state (n>20). In the first phase of the experiment, acceleration in a controlled way by an electric field gradient (Stark effect) and subsequent measurement of free fall in a Moiré deflectometer will allow a test of the weak equivalence principle. In a second phase, the antihydrogen will be slowed, confined and laser-cooled to perform CPT studies and detailed spectroscopy. In the present work, after a general description of the experiment, the present status of advancement will be reviewed, with special attention to the production and excitation of positronium atoms

Formation Of A Cold Antihydrogen Beam in AEGIS For Gravity MeasurementsAIP Conference Proceedings

The formation of the antihydrogen beam in the AEGIS experiment through the use of inhomogeneous electric fields is discussed and simulation results including the geometry of the apparatus and realistic hypothesis about the antihydrogen initial conditions are shown. The resulting velocity distribution matches the requirements of the gravity experiment. In particular it is shown that the inhomogeneous electric fields provide radial cooling of the beam during the acceleration.Comment: Invited talk at Pbar08 - Workshop on Cold Antimatter Plasmas and Application to Fundamental Physics, Okinawa, Japan, 200

Measuring the Antihydrogen Fall

The AEGIS experiment (Antimatter Experiment: Gravity, Interferometry, Spectroscopy (Drobychev et al., 2007)), aims at directly measuring the gravitational acceleration g on a beam of cold antihydrogen (H). After production, the H atoms will be driven to fly horizontally with a velocity of a few 100 m/s for a path length of about 1 meter. The small deflection, few tens of μm, will be measured using two material gratings coupled to a position-sensitive detector working as a Moiré deflectometer similarly to what has been done with atoms (Oberthaler et al., Phys Rev A 54:3165, 1996). Details about the detection of the H annihilation point at the end of the flight path with a position-sensitive microstrip detector and a silicon tracker system will be discussed

The AEGIS detection system for gravity measurements

The main scientific goal of the AEGIS experiment (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) is the direct measurement of the Earth's gravitational acceleration g on a beam of cold antihydrogen (over(H, -)). The production of an antihydrogen beam is achieved by a charge exchange reaction between Rydberg positronium and cold antiprotons. The over(H, -) beam will be accelerated up to a velocity of a few 100 m/s and the gravitational acceleration will be obtained by measuring the small vertical deflection of the beam (a few tens \u3bcm) using a Moire' deflectometer. \ua9 2010 Elsevier B.V