Interpretation of light-quenching factor measurements

We observe that the pattern of the quenching factor for scintillation light from various ions, recently studied in CaWO4 in connection with dark matter detectors, can be understood as a saturation phenomenon in which the light output is simply proportional to track length, independent of the ion and its energy. This observation is in accord with the high dE/dx limit of Birks’ law. It suggests a simple model for the intrinsic resolution of light detectors for low energy ions, which we briefly discuss.