Incoming links: Gun-type fission weapon
Gun-type fission weapons are the simplest approach and they work with Uranium-235 bombs as you can ignite it with just one explosion.
But Gun-type fission weapons don't work with plutonium, and weapon grade Plutonium is cheaper than weapon grade Uranium, so it wasn't much used.
Gun-type fission weapons don't work with Plutonium-239 because of the presence of Plutonium-240 as an impurity which leads to fizzle.
Good mentions at: youtu.be/dgBDvnqMkT4?t=252
Implosion-type fission weapons are more complicated than gun-type fission weapon because you have to precisely coordinate the detonation of a bunch of explosives.
Plutonium-based.
Its plutonium was produced at Hanford site.
Trinity Test Preparations by AtomicHeritage (2016)
Source. Appears to be a compilation of several videos, presumably each with their own separate LA-UR, though these are not noted. Credited: "Video courtesy of the Los Alamos National Laboratory Archives", TODO how to search that archive online?Trinity: Getting The Job Done
. Source. Good video, clarifies several interesting technical points:- Gun-type fission weapon were much easier to build as you don't need super synchronized charges as in implosion-type fission weapon. But they are less efficient.
- Plutonium make much more efficient usage of uranium, because you don't need to highly enrich a bunch of Uranium-235 in the first place, but rather just use way less enriched Uranium-235 to produce a bunch of Plutonium by converting Uranium-238