Efficient Rydberg positronium laser excitation for antihydrogen production in a magnetic field

Antihydrogen production by charge exchange reaction between positronium (Ps) and antiprotons requires an efficient excitation of Ps atoms up to high-n levels (Rydberg levels). We propose a two-step laser light excitation, the first from ground to n?=?3 and the second from this level to a Rydberg level n?>?15. In this study it is assumed that a Ps cloud is produced by positrons hitting a target converter located in a Penning-Malmberg trap within a uniform ~ 1 T magnetic field. We model the optical transition structure by taking into account Doppler and motional Stark effects. The predicted efficiency for population deposition in high n states is of ~30%.