An energy-tunable positronium beam produced using the photodetachment of the positronium negative ion

摘要

We report here the production of an energy-tunable monoenergetic positronium beam using photodetachment of the positronium negative ion, a bound state of one positron and two electrons. The ions were produced efficiently by bombarding a Na-coated tungsten surface with a pulsed slow positron beam and accelerated using a static electric field. On irradiating the ions with a high intensity pulsed laser light, a positronium beam with a hitherto unrealized energy range of up to 1.9 keV has been produced in an ultra high vacuum environment.