@article{
author = {Steve Fetter, Valery A. Frolov, Marvin Miller, Robert Mozley, Oleg F. Prilutsky, Stanislav N. Rodionov, Roald Z. Sagdeev},
title = {Detecting nuclear warheads},
journal = {Science & Global Security},
volume = {1},
number = {3-4},
pages = {225-253},
year = {1990},
URL = {https://scienceandglobalsecurity.org/archive/1990/01/detecting_nuclear_warheads.html},
eprint = {http://scienceandglobalsecurity.org/archive/sgs01fetter.pdf},
abstract = {In the absence of shielding, 'ordinary' nuclear weapons--those containing kilogram quantities of ordinary weapon-grade (6 percent plutonium-240) plutonium or uranium-238--can be detected by neutron or gamma counters at a distance of tens of meters. Objects such as missile canisters can be radiographed with high-energy x-rays to reveal the presence of the dense fissile core of any type of nuclear warhead, or the radiation shielding that might conceal a warhead. If subjected to neutron irradiation, the fissile core of any type of unshielded warhead can also be detected by the emission of prompt--or delayed--fission neutrons at a distance on the order of 10 meters.}
}