Antimatter weapon

The paramount advantage of such a theoretical weapon is that antimatter and matter collisions result in the entire sum of their mass energy equivalent being released as energy, which is at least two orders of magnitude greater than the energy release of the most efficient fusion weapons (100% vs 0.4–1%). Annihilation requires and converts exactly equal masses of antimatter and matter by the collision which releases the entire mass-energy of both, which for 1 gram is ~9×10¹³ joules. Using the convention that 1 kiloton TNT equivalent equals 4.184×10¹² joules (or one trillion calories of energy), one half gram of antimatter reacting with one half gram of ordinary matter (one gram total) results in 21.5 kilotons-equivalent of energy (slightly more powerful than the atomic bomb dropped on Nagasaki in 1945).

Cost

As of July 2024, the cost of producing one millionth of a gram of antimatter was estimated at US $62 billion. By way of comparison, the cost of the Manhattan Project (to produce the first atomic bomb) is estimated at US$23 billion in 2007 prices. As such, Hui Chen of Lawrence Livermore National Laboratory dismissed concerns about antimatter bombs in 2008 as "unrealistic".