http://www.rawstory.com/news/mochila/Suitcase_nukes_said_unlikely_to_exi_11102007.html
I've been studying up this past month on nuclear warheads (mainly from a survival point of view) and came to the realization that the physics simply don't work out to support the notion of a "suitcase nuke".
Exhibit A: The DoD Nuclear Effects Handbook
Notice that there are 3 materials capable of "supercriticality" (capable of fission from low energy neutrons) and that none of them are capable of achieving it at normal densities. They must be compressed IAW 1.48.
This is because the neutron flux isn't linearly proportional to mass. Which gives rise to the problem; there must be a minimum mass of fissionable material capable of achieving supercriticality.
And according to the same source, a 100% efficient reaction of 2 ounces of material generates roughly 1 kT.
Unless my math is off (and I'm certainly no nuclear physicist) this has to be somewhere in the neighborhood of the smallest possible yield.
Turns out the early Ranger test and later Buster tests were looking for this floor.
http://www.radiochemistry.org/history/nuke_tests/ranger/index.html
http://www.radiochemistry.org/history/nuke_tests/buster_jangle/index.html
and it's right on the money. 1kT. The one attempt to generate less fizzled.
The upshot of all this: A "suitcase" nuke *should* not be technically feasible. Simply too much explosive would be required to achieve supercriticality. By the time you got enough explosives around it, it'd weigh as much as a bus.
That is not to say that man-portable warheads (in the low hundreds of pounds) could not be produced. In fact, they have.
There's an area in which combining Neutron reflectors (tampers) and central neutron emitters (initiators) can make a larger chunk easier to detonate with less explosives.
But even that scale was incredibly difficult for the superpowers. Couldn't be a cake-walk for the folks we're concerned about, and truthfully it wouldn't make sense for them to try.
A large Uranium gun weapon (little boy) is easily done, portable by truck or container, and has a much bigger bang.
There is a definite threat of dirty bombs at this scale or a nuclear truck bomb, but a suitcase nuke appears to be about as feasible as a bridge made of Jell-o.
Is this just another attempt at hyperbole? Is the "suitcase nuke" the "cop-killer bullet" of the new millenium?
I've been studying up this past month on nuclear warheads (mainly from a survival point of view) and came to the realization that the physics simply don't work out to support the notion of a "suitcase nuke".
Exhibit A: The DoD Nuclear Effects Handbook
Notice that there are 3 materials capable of "supercriticality" (capable of fission from low energy neutrons) and that none of them are capable of achieving it at normal densities. They must be compressed IAW 1.48.
This is because the neutron flux isn't linearly proportional to mass. Which gives rise to the problem; there must be a minimum mass of fissionable material capable of achieving supercriticality.
And according to the same source, a 100% efficient reaction of 2 ounces of material generates roughly 1 kT.
Unless my math is off (and I'm certainly no nuclear physicist) this has to be somewhere in the neighborhood of the smallest possible yield.
Turns out the early Ranger test and later Buster tests were looking for this floor.
http://www.radiochemistry.org/history/nuke_tests/ranger/index.html
http://www.radiochemistry.org/history/nuke_tests/buster_jangle/index.html
and it's right on the money. 1kT. The one attempt to generate less fizzled.
The upshot of all this: A "suitcase" nuke *should* not be technically feasible. Simply too much explosive would be required to achieve supercriticality. By the time you got enough explosives around it, it'd weigh as much as a bus.
That is not to say that man-portable warheads (in the low hundreds of pounds) could not be produced. In fact, they have.
There's an area in which combining Neutron reflectors (tampers) and central neutron emitters (initiators) can make a larger chunk easier to detonate with less explosives.
But even that scale was incredibly difficult for the superpowers. Couldn't be a cake-walk for the folks we're concerned about, and truthfully it wouldn't make sense for them to try.
A large Uranium gun weapon (little boy) is easily done, portable by truck or container, and has a much bigger bang.
There is a definite threat of dirty bombs at this scale or a nuclear truck bomb, but a suitcase nuke appears to be about as feasible as a bridge made of Jell-o.
Is this just another attempt at hyperbole? Is the "suitcase nuke" the "cop-killer bullet" of the new millenium?