Hi guys, I'm pretty new to the site and I have a few questions, but I'll start with the most imporatant ones or at least the ones I would like answered first. Anyway so my understanding is that in a thermonuclear weapon the large majority of the explosive power comes from the fission reaction ( correct me if I am wrong), which leads to my question: What exactly does the fusion step do that makes these weapons so much stronger than pure fission weapons. Does the fast neutrons expelled during the fusion of deuterium and tritium split the U-238 atoms in the jacket or does it do something else? P.S. I hope this is in the right part of the forum.