Documents / Report
This Defense Intelligence Reference Document, dated 1 November 2010, was produced by the Defense Intelligence Agency under its Advanced Aerospace Weapon System Applications (AAWSA) Program. It surveys propulsion technologies that include chemical, ion, and nuclear fission rockets, fusion schemes, aneutronic fusion, and antimatter propulsion. It also covers radiation shielding and speculates on research needs over the next 30 years for missions from low Earth orbit to Mars, Jupiter, Saturn, and Alpha Centauri. The document concludes that aneutronic fusion promises to be an important mechanism for future space propulsion.
“Anderson”1 page
UNCLASSIFIED//F8A 8FFHil.l1k WE&i a••k>/ Appendix C: Antimatter Annihilation Rocket '' p positron antiproton stable antihydrogen atom Figure 16. Antihydrogen Atom. Using data from Table 3, the only propulsion system that can generate higher lsp than fusion will be due to antimatter annihilation. By using the Relativistic Rocket Worksheet in Appendix D, it is possible to decrease the time to reach Proxima Centauri to only 18.5 years by accelerating at 0.05 g to reach 43% of the speed of light. By using antihydrogen, two annihilation mechanisms are possible: • Electron-positron annihilation releases one energetic gamma ray (1.022 MeV) or, in the presence of a nucleus, two 0.511-MeV gamma rays. There is no effective way to reflect gamma rays, but they can be absorbed with suitable shielding and their energy converted into heat. Research into designs that convert gamma ray heat into propulsion or electrical power should proceed over the next 10 to 20 years. • Proton-antiproton annihilation releases charged and neutral pions, which decay after about 0.026 microseconds into charged muons and neutrinos. The charged pions can be used to directly generate thrust or to make electricity if they are directed by electromagnets. Unfortunately, 40% of the pions will be neutral and quickly decay into gamma radiation, which are lost from the system or absorbed in the rocket chamber wall and generate heat. Muons also decay into charged particles (electrons and positrons), along with neutrinos. Neutrinos and antineutrinos, along with their energy, are lost from the system. Novel rocket designs that capture gamma radiation with a tungsten insert allow the waste heat to be used to accelerate a propellant, such as hydrogen, to generate additional thrust. This system was proposed by Robert Frisbee and Ulrich Walter and deserves further study. 24 Efficient ways to redirect the energy of gamma rays into thrust should be a major focus of research. Antimatter propulsion is fairly straightforward since ignition is not a problem. By mixing hydrogen with antihydrogen, annihilation begins immediately. Antimatter UNCLASSIFIED/ /Pel\ err1e1111t 1!!191!! 8HLI/ 36
Not linked to a story yet.
Report, from the dia collection. The PDF is mirrored here; the original link is above. 50 pages are in the text index: search them above, or from the library's search.