2 research outputs found
GBAR Gravitational Behavior of Antihydrogen at Rest
The GBAR experiment aims to test the Equivalence Principle with antimatter by measuring the time of flight of ultra-cold antihydrogen atoms H in free fall. Antihydrogen atoms at ¯ ∼20 µK are provided by sympathetic cooling of antihydrogen ions with laser cooled ions. ions are produced via two successive reactions using antiprotons and positroniums. The synthesis of is obtained by the injection of a pulse of slow antiprotons from the AD at CERN in a dense cloud of positronium. This target of positronium is created with a positron-to-positronium converter and requires an intense source of slow positrons, a few per second. Such a source based on a small electron accelerator is under construction at Saclay. A few positrons are accumulated in a Penning-Malmberg trap from which they are ejected towards the converter to produce the target. The overall scheme of the experiment is described along with the estimated efficiency of each step