Measuring the gravitational free-fall of antihydrogen
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Author / Producer
Date
2014-10
Publication Type
Conference Paper
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yes
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Abstract
Antihydrogen holds the promise to test, for the first time, the universality of free-fall with a system composed entirely of antiparticles. The AEgIS experiment at CERN’s antiproton decelerator aims to measure the gravitational interaction between matter and antimatter by measuring the deflection of a beam of antihydrogen in the Earths gravitational field (g¯¯¯). The principle of the experiment is as follows: cold antihydrogen atoms are synthesized in a Penning-Malberg trap and are Stark accelerated towards a moiré deflectometer, the classical counterpart of an atom interferometer, and annihilate on a position sensitive detector. Crucial to the success of the experiment is the spatial precision of the position sensitive detector. We propose a novel free-fall detector based on a hybrid of two technologies: emulsion detectors, which have an intrinsic spatial resolution of 50 nm but no temporal information, and a silicon strip / scintillating fiber tracker to provide timing and positional information. In 2012 we tested emulsion films in vacuum with antiprotons from CERN’s antiproton decelerator. The annihilation vertices could be observed directly on the emulsion surface using the microscope facility available at the University of Bern. The annihilation vertices were successfully reconstructed with a resolution of 1–2 μmon the impact parameter. If such a precision can be realized in the final detector, Monte Carlo simulations suggest of order 500 antihydrogen annihilations will be sufficient to determine g¯¯¯with a 1 % accuracy. This paper presents current research towards the development of this technology for use in the AEgIS apparatus and prospects for the realization of the final detector.
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Publication status
published
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Book title
Proceedings of the 11th International Conference on Low Energy Antiproton Physics (LEAP 2013) held in Uppsala, Sweden, 10–15 June, 2013
Journal / series
Volume
228 (1-3)
Pages / Article No.
151 - 157
Publisher
Springer
Event
11th International Conference on Low Energy Antiproton Physics (LEAP 2013)
Edition / version
Methods
Software
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Date collected
Date created
Subject
Antihydrogen; Gravity; AegIS; Emulsions
Organisational unit
03449 - Merkt, Frédéric / Merkt, Frédéric
Notes
It was possible to publish this article open access thanks to a Swiss National Licence with the publisher.