Why is the hydrogen bomb dependent on the atomic bomb?

Answer 1

A hydrogen bomb is a fusion nuclear weapon, and the "regular" atomic bomb is a fission one. Both are an example of an "atomic bomb" in the general sense. But we know what you're asking, and here's the answer. In a fission weapon, subcritical masses of fissile material (usually plutonium) are driven together with conventional explosives to cause criticality, supercriticality and the blast. In a hydrogen bomb, the only way to get things hot enough for fusion to begin to occur is by virtue of the heat generated by a fission weapon. A fission blast will, if things are set up correctly, set off a fusion blast. Big, big, bigboom! That's the long and short of it. To build a hydrogen (fusion) weapon, you have to build a fission bomb "around" or "up against" components to cause fusion to occur in the heat of the fission reaction when that fission bomb goes off. Our sun is a gigantic fusion machine. It is similar to a hydrogen bomb in that both fuse hydrogen into helium. On the sun, it happens all the time in a continuous event. Here on earth, it's a one-shot affair and a massive boom!