On the face of it, I just don't think such a weapon is possible, at least with any technology available now or in the foreseeable future. As I've said, this is well out of my area of expertise, but such a device would require, at the very least, the suspension of Newton's Third Law of Dynamics.

Personally, I put claims such as these in the same category as perpetual motion machines, mermaids, and shape-shifting reptileans from the Perseids. Possible, I suppose, but I'd have to see it with my own eyes before I believe it.

Onward and upward,
airforce