Calculation of Attenuated Space Charge Profile Obtained by Pulsed-electroacoustic Signal Passed through Polymer Insulator before Charge Injection

Abstract

Acoustic attenuation of a pulsed electroacoustic (PEA) signal passed through a low- or a high-density polyethylene film is studied using the Kelvin-Voigt model for a viscoelastic material. The transfer functions of the low- and high-density polyethylene films in the PEA system are obtained based on the viscoelastic theory, which allow us to directly calculate acoustic attenuations in the polyethylene films. The calculated acoustic waveforms passed through the polyethylene films show good agreement with the measurements. By using this method, theoretical space charge profiles in the low- and high-density polyethylene films before a charge injection are obtained. This technique is useful for a calibration of the PEA system at the initial condition.