Electron Plasma Oscillations

Abstract

Electron plasma oscillations are excited by a beam of fast electrons in a stabilized low‐pressure mercury discharge. Probe measurements reveal that the uhf fields are localized in thin layers, the plasma density and frequency of which follow Langmuir's law. The beam of fast electrons traversing such an oscillation layer becomes velocity modulated, and excitation conditions result from drift time and bunching considerations similar to those in a klystron. A sealed‐off tube described covers a frequency range between 800 and 4000 Mc (five modes) without changing or matching any resonance circuit.