Gain competition in multitone helix traveling wave tube amplifier

Summary form only given. We study the non-linearities of the wave-beam interaction for a helix travelling wave tube amplifier with multiple input frequencies. Particle codes like MAGIC and Christine are utilized to examine the effect of the wave-beam non-linear interaction on the gain competition among the fundamental frequencies and as well as the intermodulation and harmonic products. The physical observations of the amplitude and phase of the wave from these simulations are being examined for approaches to improve linear operation with multiple frequencies. A Varian helix travelling wave tube with a frequency of operation from 1.7 to 2.4 GHz is used for initial experiments. We present results of the particle code simulations and compare them with preliminary experimental measurements.