Position-sensitive spectroscopy of ultra-cold neutrons with Timepix pixel detector

We present an implementation of the silicon pixel device Timepix for position and energy-sensitive detection of ultra-cold neutrons (UCN) with an efficiency of 70% and a spatial resolution of 5.3 μm. A layer of 400 μg/cm2 of 6LiF deposited onto the Timepix sensor surface was used as a neutron converter. The energy of each detected neutron is measured using standard time-of-flight (TOF) technique. Thus, for each detected neutron the position and energy is determined. We demonstrate this technique on the real-time measurement of energy- and position-dependent reflection of UCNs from a bent foil of stainless steel making direct visualization of total reflection angle for different neutron energies.