Ultra-cold neutrons (UCN) are neutrons with small kinetic energy—so small that UCN cannot penetrate the material wall and are trapped by the effective Fermi's material potential (~300neV). This energy corresponds to a velocity of less than 7 m/s and an effective temperature of 0.005 K.3 UCNs can be stored in “bottles” for times approaching the βdecay lifetime of the neutron (~ 900 s). Experiments with bottled UCN can offer orders-of-magnitude improvement for various precise measurements of neutron properties that are sensitive to physics beyond the standard model. Ultra Cold Neutrons are generated in several world laboratiries (ILL Grenoble, Los Alamos NL, PSI Villigen, ...).

The main goal of the project is to design a position sensitive detector of UCNs with high efficiency (~90%) and very high spatial resolution (~1 um). We are using Timepix pixel device adapted by evaporation of very thin convertor layer (less than 1 um) onto its surface. Detection efficiency of UCNs reaches 70% and spatial resolution is about 2.3 um.