SMT Design Issues for 2225 Capacitors in High Power RF

We are building a plasma diagnostic to monitor MHD phenomena in tokamak.

As part of the development, we need high-voltage, high-power RF capacitors to tune and match an inductive load. This application is similar to a small induction heater, with the following operational parameters:

RF Power 2-4 kW

Frequency 50-300 kHz

RF Voltage 500-1000 V

RF Current 50-100 A

Duty Factor would be 10 second pulses 10 minutes apart with continuous operation at lower power for testing and calibration.

We need to build two digitally adjustable capacitors (0.6-5.0 uF and 0.1-9.0 uF) out of smaller surface mount components. We expect to use approx one thousand 2250 capacitors on twenty 6U pc boards.

Does anyone have a reference design or even a photograph for board like this. I've been searching at MRI and Ham radio websites, but I haven't found anything useful yet.

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