Position and gain non-uniformities in Helium-3 filled position sensitive proportional counters

Helium-3-filled position sensitive detectors (PSDs) comprise the neutron sensing component of many neutron imaging arrays at scattering laboratories around the world, including SNS, NIST, CSNS, ACNS and others. This basic detector technology is decades old, but gradual improvement in detector electronics, increases in detector length, and tighter position resolution requirements have driven a need for improvements in detector performance. As an experienced manufacturer of PSDs, Reuter-Stokes has collaborated with neutron scientists and end users from around the world to drive improvements to PSD manufacture and testing procedures over the last decade. Here, we describe our work to understand detector defects, and detail detector testing methods which we have developed to ensure and improve PSD quality.