> I would question if it is even possible to develop a micro-BH in these conditions.
You’re right, it can’t. The production of a micro-black hole by either a particle collider or a nuclear explosion would only be possible under a very peculiar and highly unlikely theory of physics. Further, from a thermonuclear explosion the implosion generated in the core isn’t even powerful enough to generate more conventional subatomic particles such as hyperons.
The very peculiar and highly unlikely hypothesis that micro-blach holes is based on this. Space needs to be assumed to have 10 dimensions (string theory) or 11 dimensions (M theory). If space actually has fewer dimensions than that, for instance 3 dimensions in the standard model of quantum mechanics, then neither a particle collider or nuclear explosion could generate black holes.
But let’s suppose that space has 10 or 11 dimensions. Then all but 3 of these are rolled up in a Calabi-Yau manifold with a length scale similar to the Planck scale, right. Under those conditions it is STILL true that neither a particle collider or nuclear explosion could generate black holes.
In order for a black hole to be accessible to a powerful particle collider, the Calabi-Yau manifold has to be unravelled, and the sizes of the rolled-up dimensions would have to be anisotropic – different in different directions. Even if this unlikely happenstance was true, it is STILL true that neither a particle collider or nuclear explosion could generate black holes.
In order for a black hole to be accessible to a powerful particle collider, the largest of these unravelled rolled up dimensions would have to satisfy the extra condition of being be of a size of order 10^20 times the Planck length, fine tuned in size to a hundred billion billion times as big as physicists think it ought to be. The likelihood of that is so close to zero as not worth stating.
And even so, a black hole could still not be created by a nuclear explosion – even a thermonuclear explosion generates nowhere near enough energy per subatomic particle. The LHC generates 15,000,000 times as much energy per subatomic particle as an atomic fission bomb, and 3,600,000 times as much energy per subatomic particle as a hydrogen bomb.