Scintillation response of molecular cluster to charged particles

The scintillation response of rare gas clusters impacted with an ion beam was measured to investigate the size effect of scintillation efficiency. The clusters were produced by supersonic expansion method, and the average size was determined with the analysis of the Rayleigh scattering measurement. The scintillation of argon clusters induced by 3 keV Ar⁺ beam impact was measured with the photon counting method. It has been found that the number of scintillation photons per pulse is not proportional to the backing pressure, i.e. the molecular density. The scintillation efficiency per molecular density increased with the cluster size.