Surface analysis of a GaAs electron source using rutherford backscattering spectroscopy

We experimented with Rutherford backscattering spectroscopy to measure the amount of cesium on the surface of a GaAs photocathode activated in negative electron affinity (NEA) conditions. The surface analysis was performed both immediately after activation of the source in NEA condition and also some time after its total spoiling. Results showed that cesium did not desorb from the GaAs surface. With any further cesium feeding to reactivate the surface, the cesium accumulated on the surface until a saturation level was reached