Theory of a Plasma Negative Resistance Amplifier

摘要

The purpose of this paper is to present the theory of a plasma negative resistance amplifier based on an approximate quasi‐electrostatic model of a modified quadrupole cavity containing a plasma column and hyperbolic quadrupole electrodes with side resonators. The theory is extended to plasmas with finite collision frequencies in a finite magnetic field. By use of a nonlinear equation of the electron motion obtained by expanding the time varying applied electric field in Taylor's series, it is shown that the electrons in a plasma column behave as a nonlinear reactance and that a net signal amplification can be realized when sufficient pump‐power is properly applied. It is also shown that the effective noise contributed from the plasma can be reduced by decreasing the plasma electron collision frequency or the plasma density. A preliminary experimental result which indicates the presence of a nonlinear plasma interaction is described.