  In the context of the ClearMind project, we measured the scintillating
properties, as induced from from gamma ray interactions, of today available
PbWO4 crystal. We measured scintillation s yields and time constants by
measuring the signal shape measured on a fast photo-multiplier and
deconvoluting it from the instrumental effects. For the doped crystals at room
temperature, we measured a fast scintillation component, with time constants of
2 ns, 55 percent of the total light yield, and a slow component of 6 ns. We
observe a significant increase of the light yield for the slow component when
the temperature decreases and simultaneous increase of the time constants, but
no increase in the fast component light yield. Our measurements reproduce the
main qualitative features of PbWO4 crystals quoted in the literature.
Quantitatively though, we measured significantly shorter time constants and
larger light yields. This is explained by a rigorous treatment of the
instrumental contributions in the measurements. Results are discussed and
prospect for future developments, tailored for the ClearMind project, are
presented.
