CERN Accelerating science

Article
Title Linac-based positron source and generation of a high density positronium cloud for the GBAR experiment
Author(s) Liszkay, L (IRFU, Saclay) ; Comini, P (IRFU, Saclay) ; Corbel, C (Ecole Polytechnique) ; Debu, P (IRFU, Saclay) ; Dupré, P (CSNSM, Orsay) ; Grandemange, P (CSNSM, Orsay) ; Pérez, P (IRFU, Saclay) ; Rey, J -M (IRFU, Saclay) ; Ruiz, N (IRFU, Saclay) ; Sacquin, Y (IRFU, Saclay)
Publication 2013
Number of pages 5
In: J. Phys. : Conf. Ser. 443 (2013) 012006
In: 16th International Conference on Positron Annihilation, Bristol, UK, 19 - 24 Aug 2012, pp.012006
DOI 10.1088/1742-6596/443/1/012006
Subject category Accelerators and Storage Rings
Accelerator/Facility, Experiment CERN AD ; GBAR AD-7
Abstract The aim of the recently approved GBAR (Gravitational Behaviour of Antihydrogen at Rest) experiment is to measure the acceleration of neutral antihydrogen atoms in the gravitational field of the Earth. The experimental scheme requires a high density positronium cloud as a target for antiprotons, provided by the Antiproton Decelerator (AD) – Extra Low Energy Antiproton Ring (ELENA) facility at CERN. We introduce briefly the experimental scheme and present the ongoing efforts at IRFU CEA Saclay to develop the positron source and the positron-positronium converter, which are key parts of the experiment. We have constructed a slow positron source in Saclay, based on a low energy (4.3 MeV) linear electron accelerator (linac). By using an electron target made of tungsten and a stack of thin W meshes as positron moderator, we reached a slow positron intensity that is comparable with that of 22Na-based sources using a solid neon moderator. The source feeds positrons into a high field (5 T) Penning-Malmberg trap. Intense positron pulses from the trap will be converted to slow ortho-positronium (o-Ps) by a converter structure. Mesoporous silica films appear to date to be the best candidates as converter material. We discuss our studies to find the optimal pore configuration for the positron-positronium converter.

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 Journalen skapades 2023-06-09, och modifierades senast 2023-06-09


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