Abstract
A sheet-beam Extended Interaction Klystron (EIK) is being developed at W-band to demonstrate the enhanced power capability, compactness, and relatively high gain per unit length that have been predicted for the device. The EIK is powered by a 19.5-kV, 3.3-A sheet beam having dimensions of 0.32 mm × 4 mm. A beamstick for the device has achieved 98% current transport efficiency over a distance of 2 cm in a uniform magnetic field of 8.5 kG. Particle-in-cell simulations using MAGIC-3D and ICEPIC have predicted saturated output power of almost 10 kW from the EIK. A 3-cavity version of the device is predicted to have a saturated gain of >30 dB with an interaction efficiency of ∼16%. The spent-beam energy distribution is compatible with a depressed collector that can increase the overall efficiency to >30%.