A new technique for a complete study of space charge

The present work is concerned with the development of a new technique for simultaneous measurements of space charge profiles and TSDC spectra on polymer sheets without manipulating the sample and dismantling the measuring cell. During the TSDC run, the space charge profile is measured at several temperature levels by the new Alternating Thermal Wave Method (ATWM). So, the change in density and position of the space charge during the thermo-stimulated discharge may be followed. A controlled thermo-electrical module is used to generate both the linear temperature rise required by TSDC and the small alternating temperature variations around each chosen temperature level required by the ATWM. Experimental results obtained on polymethylmetacrylate (PMMA) and polypropylene (PP) samples are given.