Microchannel Plates with Quad Timepix3 Detector (MCP/TPX3) for Time-of-Flight Neutron Imaging

Microchannel plates (MCPs) with a quad Timepix3 readout have emerged as a promising neutron imaging camera for neutron imaging with time-of-flight (TOF) capability. The detector comprises a pair of chevron-stacked MCPs coupled to a quad Timepix3 readout in a vacuum enclosure. To make the detector neutron-sensitive, one of the MCPs is doped with neutron absorbers such as
¹⁰
B and
^nat
Gd. The Timepix3 readout is data-driven and zero-suppressed readout. Each Timepix3 chip has 256 × 256 pixels, and each pixel size is 55 × 55 μm
²
. It can record the time-of-arrival and time-over-threshold information of every hit in a pixel simultaneously, up to 80 Mhits/s per chip. The timestamping of each hit enables the detector to do TOF imaging, which offers significant advantages over traditional neutron imaging. The ToF capability allows the detector to perform more advanced energy- resolved neutron imaging techniques. In this work, we present a neutron imaging camera capable of TOF imaging with a sub-55 μm spatial resolution and high rate capability. The detector demonstrated a rate capability of ≤ 120 Mhits/s, a neutron efficiency of ≥ 30% at 4.2A°,sub-μs time resolution for thermal and cold neutrons, a gamma sensitivity of ≤ 10
⁻²
and an active area of 28.2 × 28.2 mm
²
. The result of a Bragg-edge imaging using nickel powder is presented.