The relevant Wikipedia page has some decent diagrams - from the original Ivy Mike Sausage style cylindrical secondaries through to very modern designs like the W88:<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Thermonuclear_weapon" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Thermonuclear_weapon</a><p>I can also recommend &quot;Dark Sun&quot; by Richard Rhodes for more details.