Erik Jongewaard

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.

Product improvement efforts for a 75 MW pulsed PPM focused X-band klystron for use in the Next Linear Collider

SLAC has been engaged in the development of a 75-MW pulsed PPM focused X-band klystron to be used in the Next Linear Collider (NLC). CPI was asked to participate in a cooperative project with SLAC engineering to help improve the mechanical design of the RF circuits to reduce fabrication costs and to improve the thermal performance of the magnetic circuits. CPI was also tasked to fabricate one complete RF circuit and a complete set of magnetic circuits incorporating the improvements. Data are presented showing the mechanical design improvements of the RF circuits and the associated ppm focusing circuits. Thermal and magnetic analysis results are also presented showing improvements in the thermal stability of the ppm focusing circuits.

Increasing Klystron Efficiency Using COM and BAC Tuning and Application to the 5045 Klystron

The Core Oscillation Method (COM) and Bunch-Align-Compress (BAC) cavity tuning schemes are discussed and applied to the re-design of the 5045 klystron towards achieving the highest efficiency micro-perveance 2.0 tube ever built.

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.

Stability review of SLAC's L-band sheet beam klystron

A review of L-band sheet beam development at SLAC National Accelerator Laboratorys Klystron Department. The measured current density profile of a 40:1 elliptical beam is presented. A review of instabilities discovered while simulating the klystron are presented.

Autopsy report on three SLAC X-Band Klystron output circuits

Three different SLAC designed and fabricated X-Band (11.424 GHz) Klystrons, including both solenoid and PPM focused, have reached end of life status and the output circuits have been cross sectioned and SEM analyzed. This paper will provide a brief overview of the SLAC X-Band Klystron development program and discuss the autopsy results on the output circuits for the three klystrons, all of which have operated at peak power levels exceeding 50 MW.