[Tuna-Fish]

Assuming 1kg of antimatter can be used to hover 1kg of matter and that your hoverboard could carry 80kg, should it's containment fail, it would detonate with the force of 3.4 gigatons of tnt. That's roughly equivalent with the entire present nuclear arsenal of the united states, and would cause 3rd degree burns out of direct thermal radiation over 300 kilometers away.

So, umm, no.

[jacques_chester]

Antimatter is definitely ridiculously dangerous stuff in macro quantities.

Though strictly speaking, from a bomb-building point of view, it would be very difficult to design a weapon where matter-antimatter mixing happened more or less completely and simultaneously. Otherwise you "merely" have a series of uncontrolled multi-megatonne explosions in an increasingly large area, instead of a single multi-gigatonne explosion.

[Tuna-Fish]

That "increasingly large area" would fall entirely inside the fireball (and likely within a few-meter radius), and the detonation would basically indistinguishable from it all going off in one go.

Disintegrating the device is a serious problem for nuclear bombs, because when they break themselves up, they leave otherwise good material unused. For an antimatter bomb, splashing the AM uncontrollably would, if anything, speed up the initiation. (After the AM and the normal matter around it is ionized, the particles home for the closest thing to annihilate with. AM basically does all the work of the weapons designer for him.)

[vl]

Hmm, how about using two nukes to create light pressure from the two ends of initially split charge of hydrogen and anti-matter hydrogen? Or, however challenging by itself - creating spherical cavity in the hydrogen bomb to push normal matter to antimatter in the cavity for awhile.