H-bomb works like this: You need to initiate fusion. For this you actually don't need Uranium or Plutonium, you just want fusion to occur in Hydrogen. However f

H-bomb works like this: You need to initiate fusion. For this you actually don't need Uranium or Plutonium, you just want fusion to occur in Hydrogen. However fusion only occurs when temperatures are extremely high and kept that way for small slice of time. This can be achieved by - guess what - firing fission bombs (i.e. regular atomic bomb)! However you can't start fusion by firing just one atomic bomb because fusion material will just fly off. You want fusion material to experience extreme pressures and temps. So - again guess what - we fire two or more nuclear bombs precisely at the same time with fusion material in the center. Another way is to use reflector so that energy from fission can be concentrated on fusion material. That's pretty much it. So each H-bomb may carry one or more regular A-bombs. A side story, which is the most amazing part, is that this whole process was worked out as mathematical theory and huge amount of time and money spent on the faith that math would work out. The math was so complicated that physicists needed computers to do that. That was back in late 40s and computers used valves and almost never worked. The story is that they finally gave up on computer and physicists would sat through many many days and nights calculating everything by hand and double checking. And all that finally worked exactly what math had predicated.