Yes, I'm look to see if it can power a free electron laser for converting visible light into gamma rays for transmitting solar energy from near the sun to Earth orbit. The efficiency is needed (at least 30% of visible light energy becomes gamma rays) so that the platform can deliver enough power to be profitable (within a year of operation)

Where does the 30 kW number come from? What would have to be done to make the accelerator more efficient? From the reading I've done, it looks like most of the energy gets lost via wall impacts from the beam not being straightened efficiently. Which component would have to be made better first to make this type of reactor work?

So your saying the alpha-Be9 capture to scattering ratio needs to be greater than 1 for this reactor to work. Is there a place where I can get the alpha-Be9 scattering cross section vs energy graph? And the alpha-Be9 capture cross section vs energy graph? Or is there an equation that can calculate both of these quantities roughly?