Mikolaj Habryn says:
Fusion bombs I thought used tritium as fuel and needed a Plutonium trigger or something. They are supposedly set off with some kind of inner mirrored ball with high powered lasers. Fission then fusion I believe.
The plutonium trigger is set off using conventional explosives to implode a hollow sphere of the material. While this technique is superficially similar to the gun-type triggering used by U-235 fuelled bombs, the geometry prevents the Pu-239 from fissioning prematurely. The tritium is used as a neutron source - it releases neutrons when sufficiently motivated to do so.
In a fusion, or H Bomb, the tritium (which is just hydrogen with an extra two neutrons) is that which produces the boom -- the main fuel, as it were. Its a "neutron source" only in the weakest possible sense -- the same way dynamite might be considered to need nitroglycerine as a "neutron source". (I'm not sure that people outside of the bomb building industry really know *for sure* what the geometries used in the atomic weapon that sets off the fusion reaction.) Perry