Abstract
A new method to measure the density of plasma is proposed. The principle is based on the measurement of the dielectric constant (or the impedance) of the plasma by use of FM or PM demodulation circuits. As the frequency of the HF used is fixed during the measurement, and the output of the circuit is rectified automatically, most of the difficulties which are inherent to the HF measurement can be avoided, so that this method can be used as a density measurement of pulsed discharges.
