AbstractSample charging phenomena arising in the ESCA experiment have been investigated for gold and polymer films of known thickness ranging from 5 Å to 20 μ deposited on gold either insulated from or in electrical contact with the spectrometer. Charging induced by a monochromatic x‐ray source is typically an order of magnitude greater than that induced by a nonmonochromatized source and exhibits a marked time dependence. A novel source of secondary electrons which employs a low‐power, low‐pressure mercury lamp external to the spectrometer source chamber as an alternative to an electron flood gun is described, and the charging and biasing characteristics of polymer films as a function of film thickness are discussed and demonstrated to provide an extra informational dimension for the study of polymeric materials.