  Opaque scintillators are designed to have a short scattering length such that
scintillation photons are probabilistically confined to a small region of space
about their origin. The benefit of this feature is that information on the
interaction event topology can be recorded with greater fidelity than in
traditional highly transparent media with sensors at large distances from the
light production region. Opaque scintillator detectors rely on
wavelength-shifting fibers to extract the scintillation light; however, the
efficiency of light collection has not yet been directly measured in
experiment. We measured the efficiency of light collection as a function of the
optical parameters of an opaque liquid and the distance from the origin of the
light to the fiber. We use the experimental data to validate a Monte Carlo
model of light transport and collection and discuss a simple diffusion model
that reproduces the results of Monte Carlo simulation with high fidelity. This
combination of validated models has the potential for use in predictions of
performance in various designs of future opaque scintillator detectors such as
LiquidO.
