Mass Production of Antimatter for High-Energy Propulsion

Abstract

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. The major technical dif culty appears to be the ef cient production of antimatter. Estimates based on the use of currently available technologies indicate that the equipment required to produce and store antimatter would be inef cient and expensive. Hence, potentially more ef cient processes should be examined. 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 ef cient. Several of these have been examined, and some show a signi cant improvement in ef ciency, but they may be dif cult to implement. Two methods examined will be discussed along with some technical advantages and disadvantages. In the rst 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 signi cantly 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 signi cant increase in the number of interactions that would occur and would proportionally increase the antiproton production. Nomenclature c = speed of light Ç E 0 = energy storage rate e ¡ = electron e + = positron I = beam current J / w = charm-anticharm resonance particle K + , K ¡ = kaons L 0 = luminosity l = beam interaction length Ç M = mass injection rate m p = proton rest mass n = neutron P 0 = power p = proton p = antiproton q e = electron charge S 0 , s = center of mass energy a = constant parameter c = photon e , g = ef ciencies h = scattering angle l + , l ¡ = muons m e ,m e = electron neutrinos m l ,m l = muon neutrinos p + , p , p 0 = pions q 0 = rho resonance particle r , r w = cross sections

The Antimatter Photon Drive - A relativistic propulsion system

“…One of the major hurdles to overcome will be the technology required to produce and store large masses of charged antimatter. 9 ' 10 While this has been accomplished for small quantities of antimatter, any nearterm solutions will require breakthrough technologies that are capable of storing many kilograms of positrons or antiprotons. …”

Antimatter Propulsion and its Application for Interstellar Travel: A Review

“…Presently, the production of antimatter involves the collision of highly energized protons with fixed heavy elements, for example, Tungsten. Brice N. Cassenti (January 2000) discussed two methods to improve the production rate [8], [31]. In method 1, antiprotons and pions generated due to highly energized protons colliding with the fixed heavy elements are gathered.…”

Future of Antiproton Triggered Fusion Propulsion

“…These simulations would also provide guidance for the development of a magnetic nozzle to direct the charged exhaust products. This approach may also require significant quantities of antiprotons (between 10 11 and 10 13 for each pellet), and, hence, more efficient antiproton production techniques may have to be developed than are currently available 24 .…”