Prospects for measuring the gravitational free-fall of antihydrogen with emulsion detectors

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 moiré deflectometer. The goal is to determine the gravitational acceleration g with an initial relative accuracy of 1% by using an emulsion detector combined with a silicon µ-strip detector to measure the time of flight. Nuclear emulsions can measure the annihilation vertex of antihydrogen atoms with a precision of∼ 1–2 µm rms.