Dresden 2011 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

A: Fachverband Atomphysik

A 11: Precision spectroscopy of atoms and ions III

A 11.2: Talk

Tuesday, March 15, 2011, 14:15–14:30, BAR 205

Production of Antihydrogen via Double Charge Exchange — •Andreas Müllers — for the ATRAP collaboration — Johannes Gutenberg Universität Mainz, Institut für Physik 55099 Mainz

The comparison of the 1S−2S transition in hydrogen and antihydrogen will provide an accurate test of CPT-symmetry. Antiprotons and positrons are readily stored and cooled in the same Penning trap, but separated by a potential barrier. Three body recombination, the standard method to produce antihydrogen, requires driving the particles to overcome this barrier, and therefore heating them. Since the typical depths of neutral atom traps are on the order of 0.5 K, confinement of single antihydrogen atoms produced this way has only recently been demonstrated [1]. For precision spectroscopy, a larger number of cold antihydrogen is advantageous. To this purpose, the ATRAP-collaboration is also investigating a different production scheme: Cesium is laser-excited to Rydberg states and collides with positrons, forming positronium atoms in a charge exchange reaction. These are no longer bound by the electric fields of the Penning trap and interact with antiprotons, producing antihydrogen in a second charge exchange. We developed the techniques to laser-excite Cesium atoms to high-n states within the strong magnetic fields of our Penning- and neutral-atom Ioffe-trap. Also, production of positronium atoms is reported and the first trials to trap antihydrogen made by this method were performed.

[1] doi:10.1038/nature09610