Infrared spectroscopy of surface charges in plasma-facing dielectrics

We propose to measure the surface charge accumulating at interface between a plasma and dielectric by infrared spectroscopy using as multi-internal reflection element. The surplus leads an attenuation of transmitted signal from which magnitude can be inferred. Calculating optical response perturbatively in first order Boltzmann equation for electron-hole inside solid, we show that parameter range interest classical Drude term results. Only integrated enters, opening up thereby very efficient analysis measured data.