Model-based processing for the estimation of space-charge distribution from non-contact pulsed electro-acoustic measurements

Abstract

Estimating the space-charge distribution using the pulsed electro-acoustic method requires a calibration procedure, in which a reference voltage signal is measured and used to divide the output voltage signal of the piezoelectric sensor. Such a procedure is time consuming and generally involves manually setting filter parameters whose values should be chosen to reduce ringing artifacts in the charge profile and, at the same time, preserve the bandwidth of the profile. This paper proposes a model-based estimation method called the matrix pencil that does not require a calibration procedure to retrieve the charge distribution, albeit with normalized amplitudes, and thus it paves the way for reducing data acquisition and processing times. Results on simulated and experimental data confirm the effectiveness of the proposed method in estimating the space-charge distribution in irradiated polymers.