Space-Charge Wave Amplification Effects

Andrew V. Haeff: Enigma of the Tube Era and Forgotten Computing Pioneer

“…Pursuing his earlier study of spacecharge effects, he investigated the interaction of electron streams of different velocities and discovered a new means of amplifying microwave energy. 25 Haeff called his new microwave amplifier the "electron-wave tube," now known as the double-stream amplifier. This was effectively a traveling wave tube with the helical electrode replaced by a second electron beam.…”

“…Haeff himself, in a foray into astrophysics, suggested that his doublestream effect accounted for the origin of solar radio noise, conjecturing that intermingling streams of charged particles emitted by the sun will greatly amplify an initial disturbance. 28 He also suggested that the Aurora Borealis (Northern Lights) and Aurora Australis are produced by a release of energy from streams of solar electrons that are pulled in by the Earth's magnetic field. Haeff's doublestream instability remains the subject of fundamental research today, in connection with particle accelerators and high-energy electronics, for example.…”

The Hamiltonian structure of the Whitham equations

“…These features of the interaction between confined beams and a plasma are important because they suggest ways in which p l a s m instabilities might be induced to disappear. 5. In spite of the success of the theory of the charged particle-plasma interaction, the discovery of new instabilities in these interactions and the fact that the basic results of the theory have been confirmed experimentally, this theory is at present still not sufficiently advanced to enable us to decide how important these instabilities are to the processes occurring in the different sorts of discharge.…”

Wave Amplification by Interaction with a Stream of Electrons

“…Apparently these investigators believe that this is a necessary condition for amplification, but our analysis shows that amplification is possible in much less special circumstances. An amplifier of the same type, but operating on a somewhat different principle, has been discussed more recently by Haeff,Nergaard,Pierce and Hebenstreit,10 and Hollenberg. 10 A more complete study of propagation in cylindrical guides, based on Bailey's theory 1 in which the motion of the positive ions is also considered, will be given in another publication.…”