Draft:Dragon Critical Assembly

The Dragon Critical Assembly

The Dragon critical assembly was an experiment conducted during the Manhattan Project at Los Alamos. It involved dropping a slug of enriched uranium hydride through a slightly subcritical annulus of enriched uranium hydride with a tamper of tungsten carbide or beryllium, aiming to support a chain reaction on prompt neutrons alone for about 1/100th of a second.

The experiment was designed to verify criticality based on prompt neutrons alone, which was proposed by Otto R. Frisch and approved by J. Robert Oppenheimer. The first experiments were performed with a beryllium oxide tamper, but later tungsten carbide was used to eliminate neutron moderation from beryllium.

One notable incident during the Dragon experiment occurred when a burst of 6 x 10^15 fission reactions took place, causing the cubes that composed the assembly to blister and swell.Despite this, no one was exposed and there was no contamination.