High power traveling wave amplifier experiments

Several high-power X-band traveling wave amplifiers have been fabricated and tested. The tubes have gains ranging from 13 dB to 32 dB at 8.76 GHz, and output powers ranging from 3 to 100 MW. The amplifiers are driven by the interaction of a slow space charge wave on an electron beam with an electromagnetic wave supported by the structure. The electron beam energy is 850 keV with currents in the 1-kA range. The amplifiers all operate in a single mode over a narrow frequency range. The amplifier gain increases rapidly with the beam current and with increases in the structure length. The amplifiers´ main features are summarized. The experimental results presented confirm that it is possible to design and operate a high-power traveling-wave amplifier driven by a field emission generated intense electron beam. The system design enforced operation in the asymmetric TM01 mode of the amplifier, which showed no evidence of oscillation at the gains reported