Simulation of an antihydrogen gravity experiment utilizing multiple apertures

Abstract

An analytical model and a Monte Carlo simulation of an antihydrogen gravity experiment that would employ multiple apertures are presented. Such an experiment may be possible at the CERN Antiproton Decelerator facility. The model was developed with the primary goal of reducing the experimental run time necessary to determine the direction of free fall acceleration for antimatter in the gravitational field of the Earth. The experiment would confine cryogenic antihydrogen plasma for producing antihydrogen (e.g., by three-body recombination). A cylindrical drift tube would have a horizontal axis of symmetry, with a series of coaxial apertures positioned on one or both sides of the region for antihydrogen production. The experiment would employ a detector capable of distinguishing between cosmic rays and antihydrogen annihilations. The distribution of annihilations on the drift tube would be azimuthally asymmetric for a short distance beyond each aperture within a shadow region depending on the direction of the gravitational acceleration of antimatter. The analytical model is used to determine the probability that an antiatom would annihilate within one of the shadow regions for specified experimental parameters.