How does a hydrogen bomb work?

[Aghanim]

Fusing four protons at the same time is impossible even in an actual star. That's not how proton-proton fusion works. p-p fusion follows a p-p chain.

And even in some stars, that's not the dominant cycle. See also the CNO cycle.

I stand corrected. I know about p-p chain and CNO cycle, but the main point is that both are extremely hard to start and maintain, short of using an actual star. And low power density of a sun make me more skeptical about exploding fusion reactors in every sci-fi in the world, although it make for some cool improvised weapon

Nyrath, where are you? You need to see this and correct your fusion fuel table! http://www.projectrho.com/public_html/rocket/fusionfuel.php

[Horn Brain]

Nice try, Ayatollah.

[rdfox]

Gates: Yeah, apparently the switch to external initiation was because it didn't just allow them a much higher neutron flux at initiation and thus a faster initial reaction rate (and thus many more fissions before the core blew itself apart), it also allowed much higher compression before initiation, since they could wait until compression is complete before initiating instead of it just happening when the initiator compresses enough to get the neutron flux up to the point of starting the reaction. This was a major step in increasing the size of the stockpile, since it meant you could use much less fissile material for the same yield.

[meve12]

Take a fission bomb capable of knocking over a small city.

Use the x-ray output of that "primary" (redirected in clever ways) to compress and heat deuterium/tritium/lithium (the lithium makes more tritium when bombarded with neutrons) so you get fusion reactions.

Extra oomph can be had if you use the high-speed neutrons from the fusion reactions to fission U238. A lot of extra oomph in many H-bomb designs.

I might add that some of this was derived from designs for shaped nuclear charges for Orion drives.

[Aghanim]

I might add that some of this was derived from designs for shaped nuclear charges for Orion drives.

I think Orion drive shaped nuke was derived from this...