Unprecedented intensity of a low-energy positron beam

A new in-pile γ -converter and Pt-moderator was recently installed at the neutron induced positron source NEPOMUC. The intensity of the moderated positron beam is unprecedented and amounts to ( 9.0 ± 0.8 ) × 10 8 moderated positrons per second at an energy of 1 keV. Hence, the beam facility NEPOMUC provides the world highest intensity of a monoenergetic positron beam reported so far. Up to now, no degradation of the positron yield has been observed for several weeks of operation. Thus, the long-term stability of the positron beam enables experiments with high reliability.