Proposal of numerical analysis model of acoustic wave propagation and generation on PEA method

The pulsed electroacoustic(PEA) method has been widely used to observe space charge distribution in polymeric dielectric materials. In PEA method, a pulsed electric field is applied to specimen to generate an acoustic wave which amplitude is in proportion to the space charge profile. The acoustic wave is detected by piezoelectric device in the PEA system. The space charge profile can be reproduced by detected the acoustic wave profile. However, when a specimen has a different acoustic property from that of the upper electrode, detected acoustic wave contains other acoustic wave due to the difference of the acoustic property. The acoustic wave due to the difference of acoustic properties makes measurement error in the space charge measurement. The measurement error has been discussed by using theoretical equations of transmission and reflection. This method, however, could not succeed to clarify the spatial and transient acoustic phenomena. In this paper, a new numerical analysis model has been proposed to discuss the measurement error in metal-polymer composite dielectric materials in space charge measurement.