Earlier today I was talking on Discord with someone who is creating her own hard-SciFi universe, and she went off on a tangent I found interesting about fusion reactors. Her 15 kTon frigate design, about the size of a medium dropship, with an acceleration of .13 g, 2000 tons of radiators, 1000 tons of drive assembly, and 5000 tons of internal fuel, giving it about 2 days of slow burn maximum efficiency transfer. Plus the option to bolt on external fuel tanks for in-system work. All of this is powered by a 5 TeraWatt reactor.
Compare this to a McKenna, which can accelerate almost 8x faster, is 128x more massive, has only 32% of the fuel, and has 20 times more burn time eeked out of it. So...it's gotta be at least a hundred PetaWatts of reactor, right? But you'll need to contain that reactor, which means you need to tap it off for energy-lets assume you only need 10% of it's power to contain the reaction, and you have a 98% efficent way to turn the charged particles into electrical power, so only .2% of the 100,000,000,000,000 watts is turned into heat. That's still like 200 terawatts of heat to radiate. Those radiator fins must be white hot!
