Greetings and Salutations!
In late January Ampleon introduced the new ART2K5TPU LDMOS power transistor that promises 2.5kW in pulsed mode at 1dB compression and up to 76% efficiency if pushed hard. This transistor's drain voltage is spec'd to operate at up to 75V and now has integral temperature sensing FET's for thermal measuring of each die. Thermal overload shutdown can now be done more accurately.
If you look at the graphs, you will probably need water cooling as I bet over 1kW of heat will need to be removed from the package.
No distributor has these yet. I expect the price to be over $300ea.
https://www.ampleon.com/products/extremely-rugged/ART2K5TPU.htmlAlso Ampleon is offloading much of their older LDMOS power line to Flip Electronics of GA:
https://flipelectronics.com/Dan