A study of the scintillation light induced in liquid xenon by electrons and alpha particles

The authors have measured the time dependence and the intensity of the primary scintillation light in liquid xenon excited by 241Am alpha particles and 207Bi internal conversion electrons, at different electric field strengths. High purity liquid xenon was used to fill a parallel plate ionization chamber equipped with a CaF2 window coupled to a UV sensitive photomultiplier tube. The effect of the specific ionization density on the scintillation light as well as the time correlation between the light signal and the charge signal is reported. The authors demonstrate that the fast scintillation signal produced in liquid xenon by an ionizing particle provides an ideal trigger in a detector aiming at a complete three-dimensional even reconstruction with an excellent background rejection capability