Electron beam parametric amplifier with positive ion elimination

Claim 1

AN ELECTRON BEAM DEVICE COMPRISING: A SUBSTANTIALLY EVACUATED ENVELOPE; MEANS FOR PROJECTING AN ELECTRON STREAM ALONG A PATH AT A VELOCITY SUFFICIENT TO IONIZE RESIDUAL GAS MOLECULES, SAID STREAM EXHIBITING A POTENTIAL DISTRIBUTION ACROSS ITS WIDTH HAVING A POSITIVE POTENTIAL MINIMUM AT ITS AXIS TENDING TO ATTRACT ANY POSITIVE IONS OF SAID GAS TOWARD SAID AXIS; MEANS FOR SUBJECTING SAID STREAM TO A MAGNETIC FIELD HAVING FLUX LINES PARALLEL TO SAID PATH FOR ESTABLISHING A CONDITION OF TRANSVERSE ELECTRON RESONANCE; AN AMPLIFYING ASSEMBLY HAVING AN INPUT COUPLER RESPONSIVE TO INPUT SIGNAL ENERGY FOR IMPARTING MOTION TO SAID ELECTRONS ESTABLISHING TRANSVERSE-MODE ELECTRON WAVES ON SAID STREAM, A PUMP SECTION DOWNSTREAM FROM SAID INPUT COUPLER RESPONSIVE TO APPLIED ENERGY FOR DEVELOPING A PERIODIC INHOMOGENEOUS FIELD HAVING A PERIODICITY PHASED WITH SAID MOTION TO INCREASE THE MAGNITUDE OF SAID WAVES, AND AN OUTPUT COUPLER DOWNSTREAM FROM SAID PUMP SECTION FOR EXTRACTING SIGNAL ENERGY FROM SAID WAVES;