Abstract-High power wideband gyrotron backward wave oscillator operating towards the terahertz region

W. He, C. R. Donaldson, L. Zhang, K. Ronald, P. McElhinney, and A. W. Cross
http://prl.aps.org/accepted/fa07cYcdM9c12133c6286d9809d8d09987fde325b
Experimental results are presented of the first successful gyrotron backward wave oscillator (gyro-BWO) with continuous frequency tuning near the low terahertz region. A helically corrugated interaction region (HCIR) was used to allow efficient interaction over a wide frequency band at the second harmonic of the electron cyclotron frequency without parasitic output. The gyro-BWO generated a maximum output power of 12 kW when driven by a 40 kV, 1.5 A, annular-shaped large-orbit electron beam and achieved a frequency tuning band of 88-102.5 GHz by adjusting the cavity magnetic field. The performance of the gyro-BWO is consistent with 3D particle-in-cell (PIC) numerical simulations