Measure the energy spectrum of inelastically back-scattered electrons for highly active alkali dynode materials

Determine the experimental energy spectrum of inelastically back-scattered primary electrons emitted from highly active alkali dynode materials at the first dynode of single-photon-counting photomultipliers, in order to replace the uniform-energy assumption used to model partially amplified signals.

Background

In the proposed single photoelectron (SPE) response model, Region B describes the energy spectrum of inelastically back-scattered electrons leaving the first dynode. The authors follow Wright’s treatment and approximate this spectrum as uniform to derive an analytical expression for partially amplified signals.

However, it is explicitly noted that for highly active alkali materials—the dynode materials of particular interest here—the experimental spectrum has not been measured. The model therefore relies on an approximation whose validity for such materials remains experimentally unverified, motivating a direct measurement of the actual spectrum.