  For ion and neutron spectrometry and imaging applications at a high intensity
pulsed laser facility, fast liquid scintillators with very low afterglow are
required. Furthermore, neutron imaging with fiber (or liquid-core) capillary
arrays calls for scintillation materials with high refractive index. To this
end, we have examined various combinations of established mixtures of fluors
and solvents, that were enriched alternatively with nitrogen or oxygen.
Dissolved molecular oxygen is known to be a highly effective quenching agent,
that efficiently suppresses the population of the triplet states in the fluor,
which are primarily responsible for the afterglow. For measuring the glow
curves of scintillators, we have employed the time-correlated single photon
counting (TCSPC) technique, characterized by high dynamic range of several
orders of magnitude in light intensity. In this paper we outline the
application for the fast scintillators, briefly present the scintillation
mechanism in liquids, describe our specific TCSPC method and discuss the
results.
