A New Concept of Thermal Neutron Counting With Sub-Microsecond Timing Resolution

Abstract

A conceptual design of a novel type of thermal and cold neutron counting detector with one-dimensional spatial resolution of m, and timing resolution as low as nanoseconds, is proposed. The detector uses microchannel plates (MCPs) doped with neutron absorbing B atoms. MCP-based detectors allow two-dimensional position localization of neutron events with resolution better than 30 m and s 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 (m) and temporal (s) resolution can be converted into 1-D spatial (m) and 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 1010 cm in the 2-D configuration and 1001 mm in the 1-D case. One-dimensional detectors can be staggered to perform imaging in two dimensions with high timing resolution.