  The GBAR experiment aims at performing the first free-fall experiment with
antihydrogen atoms in order to test the weak equivalence principle with
antimatter. Antihydrogen ions are synthesized through a double charge exchange
reaction and laser cooled to energies small enough to see gravitational
effects. Anti-ion synthesis requires a large number of antiprotons, hence high
efficiency. We report here the design of an new electrostatic deceleration
device providing low energy antiprotons of a few keV. This technique will avoid
losses inherent to the use of a degrader foil.
