Neutron imaging and tomography with MCPS

Abstract

A neutron imaging detector based on neutron-sensitive microchannel plates (MCPS) was constructed and tested at beamlines of thermal and cold neutrons. The MCPS are made of a glass mixture containing 10B and natural Gd, which makes the bulk of the MCP an efficient neutron converter. Contrary to the neutron-sensitive scintillator screens normally used in neutron imaging, spatial resolution is not traded off with detection efficiency. While the best neutron imaging scintillators have a detection efficiency around a percent, a detection efficiency of around 50% for thermal neutrons and 70% for cold neutrons has been demonstrated with these MCPS earlier. Our tests show a performance similar to conventional neutron imaging detectors, apart from the orders of magnitude better sensitivity. We demonstrate a spatial resolution better than 150 μm. The sensitivity of this detector allows fast tomography and neutron video recording, and will make smaller reactor sites and even portable sources suitable for neutron imaging.

Performance tests of boron-coated straw detectors with thermal and cold neutron beams

“…The limited availability and high cost of 3 He gas have motivated various development efforts for alternate detection technologies, with priority given to detection efficiency, spatial resolution, rate limit, cost, or any combination thereof [5,6,7,8,9,10,11,12,13,14,15]. The needs of various types of neutron scattering instruments also differ in these performance metrics.…”