Plan of NNbar experiment at the WWR-M reactor

Abstract

We propose an experiment to search for neutron–antineutron oscillations based on the storage of ultracold neutrons (UCN) in a material trap. This experiment will be competitive due to a new UCN source which is under construction at the NRC “Kurchatov Institute” – PNPI. It is expected to provide UCN densities by 2–3 orders of magnitude higher than at existing sources. The sensitivity of our experiment mostly depends on the trap size and the stored number of UCN. Simulations show that this can be increased by ∼ 10–40 times compared to the best previous experiment, dependent upon a model of neutron reflection from walls. The project currently includes designs of the UCN chamber, magnetic shielding and the detector system, as well as simulations of neutron storage and detection of annihilations events.