Resolution and Line Shape in Scintillation Counters

An experimental study has been made of some factors that determine the pulse height resolution of scintillation counter assemblies. A statistical model is developed from which an analytic expression for the ideal line shape is obtained. Excellent agreement is found with observations using an artificial light pulser. A comparison is made between noncrystalline organic scintillators and a sodium iodide crystal of similar size. It is shown that for gamma-ray detection, an important contribution to line-width originates with variations in the light collection efficiency from different regions of the scintillator.