Multiple Beam Klystrons for Accelerators and Collider Patrick Ferguson, Liqun Song, Lawrence Ives Calabazas Creek Research, Inc. 20937 Comer Drive Saratoga, CA 95070 (408) 741-8680 Patrick@CalCreek.com, RLIves@CalCreek.com www.CalCreek.com

Calabazas Creek Research, Inc. Leader in development of high power RF sources and components for fusion and high energy physics research. Products used in Europe, Asia, and the United States. Founded in 1994. 10 MW, W-Band Gyroklystron

500 kV Electron Gun for the University of Maryland Current Programs 50 MW X-Band Multiple Beam Klystron (MBK) 201 MHZ, 5 MW MBK 100 W, W-Band MEMS TWT Improved cathodes for magnetron injection guns X-Band, 100 MW Sheet Beam Gun Finite Element, Adaptive Mesh Particle-In-Cell Code Finite Element, Adaptive Mesh Trajectory Code High power windows and waveguide components 500 kV Electron Gun for the University of Maryland Additional information at www.CalCreek.com

Analytical Tools Gun and collector design – 3D Beam Optics Analysis, 3D OmniTrak, 2D Trak, 2D EGUN Magnetics – Maxwell 2D, Maxwell 3D Cavities – Superfish, HFSS, MAFIA Circuit – 21/2D KLSC, 3D MAGIC Thermal - ANYSYS

X-Band MBK Program 50 MW, 11.424 GHz MBK for accelerator research

Collector Design Collector design requires 3D magnetics and 3D beam simulations.

5 MW, 201 MHz MBK for Tevatron Number of Beams 8 Frequency 201 MHz Power 5 MW Efficiency >55% Gain 46 dB Must operate linearly 15% below saturation Must fit in space available Funded by U.S. Department of Energy Small Business Innovation Research Grants DE-FG03-004ER83916

Multiple Beam Fundamental Mode Cavity Configuration

Electron Gun Analysis

Circuit Analysis(1) Initial design of MBK circuit utilizes 2D MAGIC and KLSC. Consistency is required. Final design uses 3D MAGIC. All components cold tested before and after assembly.

Circuit Analysis(2) Induced RF voltage in the output 3D MAGIC beam-RF Interaction

Window Design Window design performed with CCR’s scattering matrix code CASCADE. Thermomechanical analysis uses ANSYS.

Anticipated Configuration Magnet coils HV ceramic operates in air Polepieces Coaxial Output (2)

10 MW, 201 MHz MBK for Tevatron Number of Beams 8 Frequency 201 MHz Power 10 MW Efficiency >55% Gain 46 dB Must operate linearly 15% below saturation Must fit in space available Funded by U.S. Department of Energy Small Business Innovation Research Grants DE-FG03-004ER83916

Cost Trade-Offs Klystron configuration based on total system cost, including power supply. Diversified Technologies Inc. provided cost comparison for solid state power supplies Number of beams based on power supply costs, cost of the electron gun, and cost of the klystron circuit

201 MHz MBK Status Phase I program successfully completed Phase II proposal due April 13, 2005 Klystron and magnet would be built, tested, and delivered in the Phase II program to Fermi National Accelerator Laboratory

DOE SBIR Solicitation Grant applications are sought for new approaches for RF amplifiers for use in future Muon Collider. The RF amplifiers must have high peak power (>30 MW), 20 MHz (2 ms pulses) to 200 MHz (0.1 ms pulses). Higher power (>100 MW) at higher frequencies (from 30 microsec. At 400 MHz to 10 microsec. at 800 MHz) are also of interest. Pulse repetition rate compatibility = 15 Hz.

30 MW, 200 MHz MBK Configuration assumes 12 beams. Beam Voltage 115 kV Current 468 A Microperveance 12.0 (effective) Efficiency 55% Circuit Length 2.96 meters

100 MW, 800 MHz MBK Configuration assumes 8 beams Beam Voltage 250 kV (solid state supply) Current 752 A Microperveance 8.0 – effective Efficiency >55% Gain 50 dB Output Power 119 MW Circuit Length 2.98 meters Phase I SBIR proposal submitted to DOE in December 2004. Currently under review.

Summary Multiple beam klystrons are currently being designed and built X-Band MBK design is complete, gun was successfully tested, and klystron is being assembled 201 MHz MBK initial design is complete. No significant problems are anticipated Technology and experience available to successfully design and build MBK at other frequencies and higher power levels