Second Method to Produce Slow Antihydrogen Atoms:
Laser-Controlled Charge Exchange

A second method to produce slow antihydrogen atoms was demonstrated in a proof-of-principle experiment by ATRAP. Two lasers excite cesium atoms into a highly excited Rydberg state. Positronium atoms are formed by a resonant charge exchange process when these atoms collide with cold trapped positrons. Antihydrogen atoms form by a second resonant charge exchange process when the positronium atoms collide with nearby trapped antiprotons. Now that we have larger plasmas of positrons and antiprotons, along with a better Cs source and better lasers, we hope to soon return to investigating and using this laser-controlled antihydrogen formation process.