High Energy Propulsion Brice Cassenti University of Connecticut

High Energy Propulsion Fusion Annihilation Photon

Fusion Energy Binding energy Reactions Propulsion

Binding Energy

Some Fusion Reactions

Nuclear Reactions DT Fusion Reaction Uranium Fission Lithium Fission

Fusion Reactions The DT reaction And Lithium fission reaction Are equivalent to

Reaction Cross-Section

Reaction Kinetics Rate - Parameter - Velocity depends on temperature – – k is Boltzmann’s constant

Rate vs. Temperature “nuclear fusion reactor pictures”

Thermonuclear Weapon

Magnetic Confinement Fusion Power Tokamak

Magnetic Confinement Fusion Power Mirror “magnetic mirror nuclear fusion reactor pictures”

Inertial Confinement Fusion Power

Fusion Rockets Magnetic Mirror – End fields unequal: preferential exhaust Tokamak – Power to expel high speed plasma Inertial Confinement – Magnetic nozzles align pellet products

Orion

Daedalus Study British Interplanetary Society From Nicolson “The Road to the Stars”

Daedalus

Medusa

Medusa Specific Impulse: 100, ,000

Matter-Antimatter Annihilation  Positron-Electron Annihilation

Antiproton-Uranium Nucleus Annihilation + p p n

Courtesy of G. Smith

Pellet Ignition

Tritium Fuel Considerations Tritium is naturally radioactive – Beta decay – Half-life ~12 years Tritium requires cryogenic storage Lithium-6 is not radioactive Lithium-6 does not require cryogenic storage

Pellet Construction

Hybrid Fusion-Fission Nuclear Pulse Propulsion Use of Li6 – Reduces tritium handling problems – Decreases specific impulse System can be developed in a two step process – Use fusion to boost the specific impulse of a pulse fission rocket – Evolve to a full hybrid system

Typical Pellet Geometry Core radius0.05 mm Fuel Radius1.00 cm Tungsten Shell Thickness0.10 mm Antiproton Beam Radius0.10  m Uranium Hemisphere Radius0.30 mm

Typical Pellet Performance Antiproton Pulse2x10 13 for 30 ns Maximum Field24 MG Pellet Mass3.5 g Specific Impulse –600,000 s for 100% fusion –200,000 s for 10% fusion – 3,000 s for contained fusion

Exotic Propulsion Alternatives

Sanger Electron-Positron Annihilation Rocket By G. Matloff

Proton-Antiproton Reaction

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Pion Rocket By R. Forward Isp: 10,000,000 sec

References Kammash, T., (editor), Fusion Energy in Space Propulsion, Volume 167 Progress in Astronautice and Aeronautics, American Institute of Aeronautics and Astronautics, Washington, DC,, Kammash, T, Fusion Reactor Physics, Ann Arbor Physics, Inc. Ann Arbor, MI, Manheimer, W.M., An Introduction to Trapped-Particle Instability in Tokamaks, Energy Research and Development Administration, Washington, DC, Miley, G.K., Fusion Energy Conversion, American Nuclear Society and U.S. Energy research and Development Administration, Chicago, Miyamoto, K., Plasma Physics for Nuclear Fusion, The MIT Press, Cambridge, MA, Vedenov, A.A., Theory of Turbulent Plasma, National Aeronautics and Space Administration, National Science Foundation, and Isreal Program for Scientific Translations, Jerusalem, 1966.