Weakly bound positron-electron pairs in a strong magnetic field

摘要

Weakly bound positron-electron pairs have been created in vacuum following low energy positron bombardment of a surface held at a temperature close to 4 K. The pairs, which behave as magnetized positronium atoms in the strong (> 1 T) magnetic fields used in this experiment, were detected following their field ionization using an arrangement of Penning traps. Yields, which at highest are around 5 x 10(-6) per incident positron, are presented and compared with previous work. Measurements of the behaviour of the yield as the distance from the production target to the ionization well was varied are presented and discussed, as are results taken for a fixed well at different magnetic fields. Both data sets were found to be consistent with a model in which the positronium moves across the magnetic field lines with a constant drift speed.