Readout for a large area neutron sensitive microchannel plate detector

Abstract

A neutron sensitive microchannel plate (MCP) detector was developed for neutron imaging on the beamline of a compact pulsed hadron source (CPHS). The detector was set up with a Wedge-and-Strip Anode (WSA) and a delay line anode readout to compare the spatial resolution and throughput with these two anodes. Tests show that the WSA readout is suitable for small area imaging with a spatial resolution of 200μm with low energy X-rays in a 50mm diameter MCP–WSA assembly. However, the spatial resolution deteriorated to ~2mm in a 106mm diameter MCP–WSA assembly because the noise caused by the parasitic capacitance is 10 times larger in the larger assembly than in the 50mm diameter assembly. A 120mm by 120mm delay line anode was then used for the 106mm MCP readout. The spatial resolution was evaluated for various voltages applied to the MCP V-stack, various readout voltages and various distances between the MCP V-stack rear face and the delay line. The delay line readout had resolutions of 65.6μm in the x direction and 63.7μm in the y direction and the throughput was greater than 600kcps. The MCP was then used to acquire a neutron image of an USAF1951 Gd-mask.