High efficiency thermal neutron imaging with sub-microsecond timing resolution

Abstract

A novel type of thermal and cold neutron counting detector with one-dimensional spacial resolution of <30 μm, 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 μm and ∼1 μs 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 μm) and temporal (∼1 μs) resolution can be converted into 1-D spatial (<30 μm) 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 ∼10×10 cm2 in 2-D configuration and ∼100 × 1 mm2 in the 1-D case. One-dimensional detectors can be staggered to perform imaging in two dimensions with high timing resolution. © 2006 IEEE.