In the real world, deuterium isn't explosive. It's used in nuclear reactors to prevent them from exploding, precisely because it DOESN'T do what it does in TPT.
i want "unmodified" deuterium to make it more realistic because i think in the real world we can't make deututerium last more
With further tests, it DOES work with just the one detonator, placed in the centre and with max-life DEUT. It's better with a TTAN casing, since the TUNG shatters under pressure before all of the HYGN has fused.
I experimented with your design and found that if you put another DEUT bomb in the middle of the HYGN, it fuses. You MIGHT then get away with removing the ones at the ends, I haven't tried it so I'm not sure. Also, make sure you !set life deut 99999, to get the most 'bang' from your detonator.
That's the way. Some of the HYGN is still just burning off, though. Try placing more little DEUT bombs at the front and sides of the bomb, or else replace the casing with something a bit more durable (so the HYGN is contained long enough to fuse - it should only take a few frames)
Also, a user named SandwichLizard recently made a tutorial. Search user:sandwichlizard, in date order, and look for Fusion Tutorial (or something along those lines).
On the right track, but that's still just fire, not a nuclear explosion. I made id:1864023 to ROUGHLY show the principles involved. It's not constructed like a real one, and as a bomb it's awful - it just shows what the HYGN is supposed to do.