  The response of a position-sensitive Li-glass scintillator detector to
$\alpha$-particles from a collimated $^{241}$Am source scanned across the face
of the detector has been measured. Scintillation light was read out by an 8 X 8
pixel multi-anode photomultiplier and the signal amplitude for each pixel has
been recorded for every position on a scan. The pixel signal is strongly
dependent on position and in general several pixels will register a signal (a
hit) above a given threshold. The effect of this threshold on hit multiplicity
is studied, with a view to optimize the single-hit efficiency of the detector.
