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Register a new userA Technique for Directly Measuring the Gravitational Acceleration of Antihydrogen
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The gravitational force on antimatter has never been directly measured. A method is suggested for measuring the acceleration of antimatter $(bar g)$ by measuring the deflection of a beam of neutral antihydrogen atoms in the Earths gravitational field. While a simple position measurement of the beam could be used, a more efficient measurement can be made using a transmission interferometer. A 1% measurement of $bar g$ should be possible from a beam of about 100,000 atoms, with the ultimate accuracy being determined largely by the number of antihydrogen atoms that can be produced. A method is suggested for producing an antihydrogen beam appropriate for this experiment.
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The main goal of the AEgIS experiment at CERN is to test the weak equivalence principle for antimatter. AEgIS will measure the free-fall of an antihydrogen beam traversing a moire deflectometer. The goal is to determine the gravitational acceleration g for antihydrogen with an initial relative accuracy of 1% by using an emulsion detector combined with a silicon micro-strip detector to measure the time of flight. Nuclear emulsions can measure the annihilation vertex of antihydrogen atoms with a precision of about 1 - 2 microns r.m.s. We present here results for emulsion detectors operated in vacuum using low energy antiprotons from the CERN antiproton decelerator. We compare with Monte Carlo simulations, and discuss the impact on the AEgIS project.
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