Which bomb design uses a gun-type mechanism to shoot one subcritical piece into another?

Which bomb design uses a gun-type mechanism to shoot one subcritical piece into another?

• A. Fat Man bomb
• B. Tsar Bomba
• C. Little Boy bomb
• D. Ivy Mike

Answer: (C)

A gun-type mechanism gathers a supercritical mass by firing one piece of fissile material into another using a conventional explosive. This simple approach was used in the Little Boy design, which relied on uranium-235 and a gun-barrel to bring two subcritical pieces together quickly to start the chain reaction. The other listed devices use different methods: Fat Man used implosion with explosive lenses to compress plutonium, Tsar Bomba was a large three-stage thermonuclear device, and Ivy Mike was a test of a cryogenic fusion (not a fission gun-type weapon). Hence, the gun-type mechanism is best represented by the Little Boy.

A gun-type mechanism gathers a supercritical mass by firing one piece of fissile material into another using a conventional explosive. This simple approach was used in the Little Boy design, which relied on uranium-235 and a gun-barrel to bring two subcritical pieces together quickly to start the chain reaction. The other listed devices use different methods: Fat Man used implosion with explosive lenses to compress plutonium, Tsar Bomba was a large three-stage thermonuclear device, and Ivy Mike was a test of a cryogenic fusion (not a fission gun-type weapon). Hence, the gun-type mechanism is best represented by the Little Boy.