Michael Fazio

Industrialization effort of the SLAC XL5 klystron

The SLAC XL5 klystron, which produces 50 MW at 12 GHz, is being used in several high gradient accelerators and test stands. The design has been transferred to industry and is currently being modified for ease of assembly and for cost reduction. Two klystrons of the new design will be manufactured and fully characterized.

Experimental demonstration of a 5th harmonic mm-wave frequency multiplying vacuum tube

We report the experimental demonstration of a 5th harmonic mm-wave frequency multiplying vacuum electronic device, which uses an over-moded spherical sector output cavity. In this device, a pencil electron beam is helically deflected in a transverse deflecting cavity before entering the output cavity. No magnetic field is required to focus or guide the beam. We built and tested a proof-of-principle device with an output frequency of 57.12 GHz. The measured peak power was 52.67 W at the 5th harmonic of the drive frequency. Power at the 4th, 6th, and 7th harmonics was 33.28 dB lower than that at the 5th harmonic.

High-harmonic mm-Wave Frequency Multiplication using a Gyrocon-like Device

Traditional linear interaction RF sources, such as Klystrons and Traveling Wave Tubes, fail to produce significant power levels at millimeter wavelengths. This is because their critical dimensions are small compared to the wavelength, and the output power scales as the square of the wavelength. We present a vacuum tube technology, where the device size is inherently larger than the operating wavelength. We designed a low–voltage mm–wave source, with an output interaction circuit based on a spherical sector cavity. This device was configured as a phased-locked frequency multiplier. We report the design and cold test results of a proof-of-principle fifth harmonic frequency multiplier with an output frequency of 57.12GHz.

Retrofitting the 5045 klystron for higher efficiency

The 5045 klystron has been in production and accelerating particles at SLAC National Accelerator Laboratory for over 25 years [1]. Although the design has undergone some changes there are still significant opportunities for improvement in performance. Retrofitting the 5045 for higher efficiencies and a more mono-energetic spent beam profile is presented.

200 kW CW sheet beam klystron research and development

Development of a 200 kW CW sheet beam klystron for the Office of Naval Research. Specifications, beam stability, and cathode bell jar testing are discussed.

Simulating a new low Q 6-cell X-band klystron output cavity

X-band klystron research and development has been underway at SLAC for over two decades culminating in the current workhorse X-band RF source, the XL-4. The XL-4 traveling wave output structure consists of 4-cells and will be extended to 6-cells to reduce breakdown and further improve upon the klystrons robustness. Simulations show the gradient can be reduced by roughly 25% and that the cavity is stable. The new output cavity will be cold tested and implemented on an existing XL-4 in the near future.