Trinity and Fat Man were both plutonium implosion devices. Little Boy was a gun type uranium bomb.
Little Boy was a very simple design. Take two chunks of sub-critical U235. One piece is the target, it sits at the end of a gun barrel. The other, smaller piece is shot down the barrel with explosives. When they hit, kablooey!
Plutonium implosion weapons compress a sphere of Pu239 using explosives with impeccably precise timers. The dozens of charges needed to perfectly compress the plutonium have to all go off simultaneously or the weapon will be a dud.
The added complexity of the implosion weapon made testing critical. Implosion weapons have the advantage of needing far less fissionable material so they can be made much smaller. All our current weapons are implosion weapons.
Actually, it takes almost Three Critical Masses of 90% pure U235arranged in FOUR subassemblies [three ANNULUS rings and a Cylinder...said Cylinder driven into the Tri-ANNULUS subassemblies.
Why???
Because the Critical Mass is based on a SPHERE, and the Critical Assembly is anything but, given that the Little Boy Engineers drove that Cylinder with...TNT!!!
Plutonium implosion weapons compress a sphere of Pu239 using explosives with impeccably precise timers. The dozens of charges needed to perfectly compress the plutonium have to all go off simultaneously or the weapon will be a dud.
EXPLODING WIRE detonators, invented by a Harvard Chemistry George KistiaKowsky [sp??????] expressly for this purpose...ordinary detonators are Three Orders of Magnitude too slow!!!
The added complexity of the implosion weapon made testing critical. Implosion weapons have the advantage of needing far less fissionable material so they can be made much smaller. All our current weapons are implosion weapons.
Actually, IMPLOSION is the ONLY real way to handle Plutonium as a WEAPON...Plutonium spontaniously generates another Plutonium Isotope which gives off Neutrons...Spoiling the "loose" timing of the Gun type method. Implosion is a MUST!!!
IMPLOSION requires an "INITIATOR" at the core. NOTHING ELSE is classified about Trinity-Nagasaki than the "Initiator!
As to Speculation on the Trinity-Nagasaki initiators, as well as what has replaced them...please see reply 107.
Actually, it takes almost Three Critical Masses of 90% pure U235arranged in FOUR subassemblies [three ANNULUS rings and a Cylinder...said Cylinder driven into the Tri-ANNULUS subassemblies.
Why???
Because the Critical Mass is based on a SPHERE, and the Critical Assembly is anything but, given that the Little Boy Engineers drove that Cylinder with...TNT!!!
Plutonium implosion weapons compress a sphere of Pu239 using explosives with impeccably precise timers. The dozens of charges needed to perfectly compress the plutonium have to all go off simultaneously or the weapon will be a dud.
EXPLODING WIRE detonators, invented by a Harvard Chemistry George KistiaKowsky [sp??????] expressly for this purpose...ordinary detonators are Three Orders of Magnitude too slow!!!
The added complexity of the implosion weapon made testing critical. Implosion weapons have the advantage of needing far less fissionable material so they can be made much smaller. All our current weapons are implosion weapons.
Actually, IMPLOSION is the ONLY real way to handle Plutonium as a WEAPON...Plutonium spontaniously generates another Plutonium Isotope which gives off Neutrons...Spoiling the "loose" timing of the Gun type method. Implosion is a MUST!!!
IMPLOSION requires an "INITIATOR" at the core. NOTHING ELSE is classified about Trinity-Nagasaki than the "Initiator!
As to Speculation on the Trinity-Nagasaki initiators, as well as what has replaced them...please see reply 107.
I was reading some material on Los Alamos and didn't remember seeing anything differentiating the bombs.
But I did run across the verse written by an unknown author that was circulating around Los Alamos before the test, a "result of the anxiety surrounding the possibiity of a failure of the test." You probably have seen this before, but here it is for those who haven't:
"From this crude lab that spawned a dud,
Their necks to Truman's axe uncurled
Lo, the embattled savants stood,
and fired the flop heard round the world."
Heh!