Apropos of nothing, back in 1989 I wrote a spec script for TNG which featured the dead hulk of the DDM, which was endangering a solar system just by its proximity because neutronium would be so dense (I think the formula I read was that core density neutron star material was 3*10 to the 25th power kilograms per cubic centimeter or something) the thing's own gravity would disrupt planetary orbits. I did the math to figure out the mass of the DDM if it was made of such neutron star material, and quickly realized that the amount of energy necessary to propel such a thing was so incredible that anything capable of producing that kind of power in such a hostile internal environment would by its very nature be effective invulnerable to something as comparatively puny as nuclear weapon, said fusion blast being comparatively a drop of gasoline in a forest fire. I turned to my science buff buddy and said, "How would at 100 megaton blast damage something like that?" He said, "It wouldn't," which got me thinking about how the machine would work and what would explain it being apparently deactivated by such a relatively puny blast.
I should post the script someplace just for giggles.