High efficiency thermal neutron imaging with sub-microsecond timing resolution

A novel type of thermal and cold neutron counting detector with one-dimensional spatial resolution of <30 mum, and timing resolution as low as <50 nanoseconds, is proposed. The detector uses microchannel plates (MCPs) doped with neutron absorbing ¹⁰B atoms. MCP-based detectors allow two-dimensional position localization of neutron events with resolution better than 30 mum and ~1 mus timing accuracy. The intrinsic temporal resolution of MCP detectors is in the subnanosecond range. In this paper we show how this combination of high 2-D spatial (<30 mum) and temporal (~1 mus) resolution can be converted into 1-D spatial (<30 mum) and ~50 ns timing resolution for each detected neutron. Another unique characteristic of the proposed neutron detector is its rather high neutron detection efficiency, exceeding 50%, as predicted by our extensive analytical modeling, accuracy of which was confirmed by the first experimental measurements. The active area of these detectors can be as large as ~ 10 times 10 cm² in 2-D configuration and ~100 times 1 mm² in the 1-D case. One-dimensional detectors can be staggered to perform imaging in two dimensions with high timing resolution.