[garmaine]

> Pure fusion weapons. It's a true pandora's box for nuclear proliferation if nuclear weapons no longer need enrichment facilities.

Is this actually a thing? My understanding is that the fusion stage of a nuclear weapon is purely to generate neutrons to trigger the 3rd, fission based stage. The destructive power of the bomb comes from the fission reactions.

[rklaehn]

An almost pure fusion bomb is technically possible and has been done multiple times. Usually it is not done for weapons designs since you got all those neutrons and can just double the yield by adding some 238U outer layer.

But e.g. the US Castle Bravo test or the soviet Tsar Bomba tests were almost pure fusion. For the Tsar Bomba they left out the 3rd fission stage. It was the cleanest bomb ever detonated in terms of radiation per yield.