Pulsed electro-acoustic method for the measurement of volume charges in E-beam irradiated PMMA

The measurement of volume charges within insulators has been attempted by various methods, including thermal, optical, mechanical, and electrical stimulation of the sample. A new method incorporating pulse electrical stimulation and pulsed acoustic detection is reported here. This technique is an extension of a previously reported [1] high frequency AC steady state electro-acoustic measurements in which electric fields at an electrode surface are determined by measuring the AC high frequency vibration of the electrode in response to a DC plus high frequency AC excitation. The use of pulse operation allows the measurements of time domain delay information which yields the spatial distribution of the volume charge.