Investigation of reliability of the calculated surface potential by the non-contact type space charge distribution measuring electrode using the pulsed electroacoustic method

The measurement of the space charge distribution using the pulsed electroacoustic (PEA) method is performed with the measurement sample sandwiched between electrodes. Recently, a new method with the air gap between the sample and the high voltage electrode has been developed to measure the space charge distribution from sample bulk to surface. This method makes it possible to investigate the relationship between the accumulated charge and partial discharge, measure the polarization charge when we applied DC voltage, measure the space change distributions from bulk to sample surface during the charge particles irradiation, and calculate the surface potential, and so on. However, the reliability of the measured accumulated surface charge and surface potential has not been investigated. Therefore, if we can correctly measure and calculate the surface potential, the measurement results have high reliability. In this study, in order to confirm the reliability of the surface potential obtained by the PEA method, we compared it with that measured by the electrostatic voltmeter. As a result, the surface potential calculated using the PEA method was about 0.9 times higher than the potential using the electrostatic voltmeter, which means that the surface potential and the amount of accumulated charge measured by the PEA method is a reliable value.