Good job on the apprehension of these crazies, but really, these guys seem to have a critical misunderstanding of how radiation actually works and kills living things.
Seriously if a device like this were scientifically possible, American would have them strapped to drones by now. The problem is that radiation is easily blocked by solid structures, but also will bathe the area closest to the emitter in the highest dose of radiation, making anyone attempting to use the weapon receive the most radiation. All the wile the intended targets would receive much lower doses, and if they are not directly exposed, probably negligible doses.
There are workable ways to do this, the most common being the "dirty" bomb, which is outlawed by the Geneva convention. It is basically a low quality nuclear weapon, on explosion the same approximate level of radiation is released, but far less damage is done. It is treated in the same category as a chemical weapon. However this is still a bomb device, not something you can point and shoot.
I do agree that these men deserve much harsher punishment though. Although they had no idea what they were actually doing, they were still essentially making an extremely dangerous internationally condemned weapon. These activities rate at about the same level of terrorism as the 9/11 attacks.
