Nuclear weapons

Nuclear Fusion

• The combination of two nuclei to form a single atom.
• The product’s mass is less than the mass of the original atoms.
• Fusion occurs most readily in a combination of the hydrogen isotopes deuterium and tritium.
• Temperature in the millions of degrees is required to initiate fusion.
• A Deuterium-Tritium fusion generates about 2.8E-12J of energy

Criticality

• In order for a nuclear reaction to be self-sustaining, there must be a “critical mass” of fissile material.
• This is the mass necessary so that, on average, at least one neutron produced by every fission goes on to trigger another fission.
• Having less than critical mass will cause the bomb to “fizzle” and have a very low efficiency.
• Actual mass required for criticality depends on the density of the mass, the shape of its configuration, and the presence/effectiveness of the neutron reflector.
• Due to natural emission of neutrons, any critical mass has a chance of beginning a nuclear chain reaction.