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 equivalenceprinciple for antimatter. AEgIS will measure the free-fallof an antihydrogenbeam traversing a moir'e deflectometer. The goal is to determine the gravitational accelerationwith an initial relative accuracy of 1% by using an emulsion detector combined with a silicon ?-strip detector to measure the time of flight. Nuclear emulsionscan measure the annihilation vertex of antihydrogenatoms with a precision of ~ 1?2 ?m r.m.s. We present here results for emulsion detectors operated in vacuum using low energy antiprotonsfrom the CERN antiproton decelerator. We compare with Monte Carlo simulations, and discuss the impact on the AEgIS project.