Glow Discharge Tube as an Amplifier

The amplification of millimeter electromagnetic wave radiation within the cathode region of a cold cathode glow discharge was correlated with the variations in the current-voltage characteristic of the glow discharge [1]. The transfer of energy from the fast electrons to the electromagnetic wave amplifies the incident radiation and also causes a decrease in discharge current, called the "negative response". The measured amplification was shown to be proportional to the negative response voltage multiplied by the electron density.