We discussed the various different sorts of fusion (deuterium/tritium, and deuterium/deuterium), the radioactivity that results from fusion, the power output of fusion, the activation mechanisms for fatman, little boy, and their modern descendents. The practicality of fusion vs biomass, specifically with regard to renewability. The possibilites and consequences of pure fusion weapons.
power output of fusion is staggering. A single pair of D-T fusion supposedly results in energy output equivalent to the average energy consumption of your typical American consumer (mostly in the form of neutron velocity (when we did the math it came out to more like .06J or something, nowhere near 10 seconds of lightbulb, let alone that claim, but still, from a single pair. D-D reactions are significantly less exciting). Otoh, it needs a hell of a lot of heat to work.
I found out that the intranuclear bonds of the strong(?) nuclear force which are the source of the energy from nuclear reactions, have mass. Welcome to advanced particle physics.
The only possible source of radiation badness from fusion reactions is the freed neutron, which goes zinging away with much energy. Odds of it creating lingering badness are apparently somewhere between slim and nonexistant, though I don’t entirely understand the whys and wherefores.
Fatman and littleboy had different activation mechanisms. One of them had a wedge and slot thing, that when brought together made critical mass (think pacman + wedge gag). Apparently an altimeter tied to explosives, blew the two sub-critical components together to make it go boom at the right height. I forget the other mechanism.
Plutonium doesn’t automatically react at critical mass. Explosives in a balanced ‘soccerball’ outside it, blow up and compress the plutonium, which then goes boom. Thermonuclear bombs (H-bombs, fission/fusion bombs), have a layer of explosives around a layer of uranium/plutonium around a layer of fusionable material, to do an additional stage to reach fusion heat. then boom.
Fusion is pretty sustainable because the sun is continually blowing lots of hydrogen our way. It depends on the gain of the reaction we would harness for power. Biomass is probably more immediately practical.
Pure fusion weapons have no fallout. We also have no clue how to make them work.
Do you feel better now? 😉