Using piezoelectric resonance effect, a new non-disturbing probe has been developed for measurement of electric fields in inductively coupled plasmas(ICP). mposed of non-metalic components, this probe minimize disturbance of electric fields. The probe measures rf electric fields (f = 3.9184 MHz) directly with proper sensitivity (E = 0.1 V/cm) and responds to both capacitive electric fields (space charge electric fields) and inductive electric fields. Some examples of useful applications for the new probe are presented, such as measurements of (1) electric fields near(inside and outside) rf coil without and with plasmas and (2) electric fields vs time during the change of capacitive mode to inductive mode.
