Mass Production of Antimatter for High-Energy Propulsion

Theoretical and experimental work completed during the past decade indicates that interstellar propulsion systems based on the annihilation of antiprotons in a propellant will be feasible during the next several decades. Currently, antiprotons are produced by colliding high-energy protons with stationary heavy-element targets such as tungsten. Other approaches, for which experimental data are available, indicate that there are production methods that are more efficient. Two methods are discussed. In the first method, antiprotons and pions are collected from the collision of high-energy protons and a heavy-element target. Many more pions are produced than antiprotons. The pions are then directed toward the same target or a different target. The collision of pions and heavy nuclei have a higher probability for the production of antiprotons and would significantly increase the number of antiprotons produced. In the second method, a recirculating electron-positron collider would produce multiple collisions near a resonance for producing antiprotons by using beam wigglers as in free-electron lasers. This technique would allow a significant increase in the number of interactions that would occur and would proportionally increase the antiproton production. (Author)