Parametric Amplification of Space Charge Waves

Abstract

By modulating a beam strongly with a high-level signal, called the ``pump'' signal, a low-level space charge wave of another frequency imposed on the beam can be parametrically amplified. With the pump frequency twice the signal frequency, 13-db gain per plasma wavelength has been observed in a movable cavity experiment. Over a 10-in. length of beam the signal has been observed to increase 41 db. When the imposed signal wave's frequency is not exactly half the pump frequency, the beam generates another wave called the ``idler'' such that ωsignal+ωidler=ωpump with both signal and idler growing exponentially with distance along the beam. In another experiment with the pump frequency lower than the signal frequency, the signal was observed to increase by 30 db over a 9.2 in. length of beam.

Nonlinear Effects in Longitudinal Electron-Stream Slow-Waveguide Systems

“…In particular, this restriction has produced severe practical consequences in the case of the fast space-charge wave amplifier. Although the amplifier produced the expected qualitative results (Ashkin, 1958), significant amounts of -33 -coupling to unwanted idler frequencies,…”

Dances of dual dynamics enable parametric oscillations under a steady force

“…Half a century later, Lord Rayleigh put this class of phenomena on a firm ground by providing a systematic analysis of this general class of parametric effects ( 3 ). Yet, it was during the 20th century that parametric oscillators and amplifiers reached their zenith by enabling a host of far-reaching and widespread applications ( 4 – 6 ). Such systems are nowadays extensively deployed in realizing low-noise electronic parametric amplifiers and detectors and in building highly versatile optical parametric oscillators, to mention a few.…”

Cyclotron wave amplification using simultaneous R. F. -coupling and D. C. -pumping

“…On the same nomograph, find the beam voltage corresponding to the slowing factor. 4. Connect the points corresponding to the cyclotron frequency and the slowing factor in the nomograph.…”