So many assumptions here.......
First, a uranium device is relatively easy to construct, a bright high school physics student can likely do it with the right equipment......however, building a
reliable device that won't kill everyone within a quarter mile of it, and building it small and lightweight enough for use by an airborne delivery vehicle, is another matter entirely. With this in mind, the yield of a device that would fall within the payload capability of the present class of Iranian missiles would likely fall within the one to three kiloton range (similar to our old tactical nukes). Further building such a device that is well enough shielded that it won't light up every gamma detector in the free world makes things even more complex. I don't believe that Iranian technology is anywhere near that sophisticated at this point.
I have it on fairly good authority that Israel has the capability to reduce most of the Islamic world to a uninhabitable glass parking lot, should the need arise.......and if attacked, they would not, for a moment, hesitate to do so. Therefore, ironically, in the dawning age of American political cowardice (thanks to the Obama voters), I find Israel the emerging last, best hope for the expansion of freedom in the Middle East.
Strange.......but interesting times we live in.......
doc
The First Nuclear device used on Japan :The only calculations needed once the concept was proven was the size of the critical mass needed to produce a sustained reaction Ie
one that would continue until all of the fuel was consumed .Initial calculations proved that about 7 kilograms = 15.4 pounds of U238 was all that was needed but they super_sized it just to make sure to about 40 pounds !
snip
dropped an 8,900-pound atomic weapon from its specially modified bomb bay. Two thousand feet above the ground, the bomb, dubbed "Little Boy" by its makers, detonated, leveling almost 90% of the city.
Fat Man and Little Boy, both weapons of unparalleled destructive power, were actually quite different. Little Boy, fueled by highly enriched uranium-235, was triggered by a simple "gun" mechanism; a small, slug-shaped piece of uranium was fired down a barrel into a larger, cup-shaped piece. This elementary design generated a destructive force of about 15 kilotons—the equivalent of 15,000 tons of TNT.
The first bomb 'little boy' was made out of a six foot long ,three inch anti aircraft gun barrel with its breech to fire half of the hemisphere into the other useing a 3" blank round to drive the uranium slug .
The two hemispheres of u238 when slammed together produced the reactive explosion . the final yield was 15 kt (+/- 20%).
The gun was a 3" (inside diameter) anti-aircraft barrel, 6.5" wide, and six feet long that had been bored out to 4" to accommodate the bullet. It weighed about 450 kg, and had a breech block weighing 34 kg. Cordite, a conventional artillery smokeless powder, was used as the propellant, and the velocity achieved by the bullet was 300 m/sec.
A much more complex implosion-type device triggered Fat Man. It consisted of a plutonium core surrounded by high explosives wired to explode simultaneously. The shock waves from these conventional explosions triggered the fission of the plutonium, which yielded a 22-kiloton explosion.
http://www.cartage.org.lb/en/themes/Sciences/Chemistry/NuclearChemistry/NuclearWeapons/FirstChainReaction/FirstNuclWeapons/LittleBoy.htm[/list]
