A key part of making an atomic bomb in your garage
is obtaining a suitable neutron deflector
. The neutron deflector
should surround the fissionable material
and be comprised solely of uranium-238
. Not only is U-238 non-fissionable
, it also has the unique ability to reflect neutrons
back to their source.
The U-238 neutron deflector serves 2 purposes:
- In a uranium bomb, the neutron deflector serves as a safeguard to keep an accidental supercritical
mass from occurring by bouncing the stray neutrons from the `bullet' counterpart of the uranium mass away from the greater mass below it (and vice-versa).
In a plutonium bomb, the neutron deflector actually helps the wedges of plutonium retain their neutrons by reflecting the stray particles back into the center of the assembly.