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Title: Antiproton Powered Gas Core Fission Rocket

Abstract

Extensive research in recent years has demonstrated that 'at rest' annihilation of antiprotons in the uranium isotope U238 leads to fission at nearly 100% efficiency. The resulting highly-ionizing, energetic fission fragments can heat a suitable medium to very high temperatures, making such a process particularly suitable for space propulsion applications. Such an ionized medium, which would serve as a propellant, can be confined by a magnetic field during the heating process, and subsequently ejected through a magnetic nozzle to generate thrust. The gasdynamic mirror (GDM) magnetic configuration is especially suited for this application since the underlying confinement principle is that the plasma be of such density and temperature as to make the ion-ion collision mean free path shorter than the plasma length. Under these conditions the plasma behaves like a fluid, and its escape from the system is analogous to the flow of a gas into vacuum from a vessel with a hole. For the system we propose we envisage radially injecting atomic or U238 plasma beam at a pre-determined position and axially pulsing an antiproton beam which upon interaction with the uranium target gives rise to near isotropic ejection of fission fragments with a total mass of 212 amumore » and total energy of about 160 MeV. These particles, along with the annihilation products (i.e. pions and muons) will heat the background U238 gas - inserted into the chamber just prior to the release of the antiproton - to one keV temperature. Preliminary analysis reveals that such a propulsion system can produce a specific impulse of about 3000 seconds at a thrust of about 50 kN. When applied to a round trip Mars mission, we find that such a journey can be accomplished in about 142 days with 2 days of thrusting and requiring only one gram of antiprotons to achieve it.« less

Authors:
 [1]
  1. Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Blvd, Ann Arbor, MI 48109 (United States)
Publication Date:
OSTI Identifier:
20630582
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 746; Journal Issue: 1; Conference: STAIF 2005: Conference on thermophysics in microgravity; Conference on commercial/civil next generation space transportation; 22. symposium on space nuclear power and propulsion; Conference on human/robotic technology and the national vision for space exploration; 3. symposium on space colonization; 2. symposium on new frontiers and future concepts, Albuquerque, NM (United States), 13-17 Feb 2005; Other Information: DOI: 10.1063/1.1867173; (c) 2005 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ANNIHILATION; ANTIPROTON BEAMS; ANTIPROTONS; FISSION; FISSION FRAGMENTS; ION-ION COLLISIONS; MAGNETIC FIELDS; MAGNETIC MIRRORS; MEAN FREE PATH; MEV RANGE; MUONS; PIONS; PLASMA; PLASMA CONFINEMENT; PROPULSION SYSTEMS; PROTON BEAMS; ROCKETS; SPACE VEHICLES; URANIUM; URANIUM 238

Citation Formats

Kammash, Terry. Antiproton Powered Gas Core Fission Rocket. United States: N. p., 2005. Web. doi:10.1063/1.1867173.
Kammash, Terry. Antiproton Powered Gas Core Fission Rocket. United States. doi:10.1063/1.1867173.
Kammash, Terry. 2005. "Antiproton Powered Gas Core Fission Rocket". United States. doi:10.1063/1.1867173.
@article{osti_20630582,
title = {Antiproton Powered Gas Core Fission Rocket},
author = {Kammash, Terry},
abstractNote = {Extensive research in recent years has demonstrated that 'at rest' annihilation of antiprotons in the uranium isotope U238 leads to fission at nearly 100% efficiency. The resulting highly-ionizing, energetic fission fragments can heat a suitable medium to very high temperatures, making such a process particularly suitable for space propulsion applications. Such an ionized medium, which would serve as a propellant, can be confined by a magnetic field during the heating process, and subsequently ejected through a magnetic nozzle to generate thrust. The gasdynamic mirror (GDM) magnetic configuration is especially suited for this application since the underlying confinement principle is that the plasma be of such density and temperature as to make the ion-ion collision mean free path shorter than the plasma length. Under these conditions the plasma behaves like a fluid, and its escape from the system is analogous to the flow of a gas into vacuum from a vessel with a hole. For the system we propose we envisage radially injecting atomic or U238 plasma beam at a pre-determined position and axially pulsing an antiproton beam which upon interaction with the uranium target gives rise to near isotropic ejection of fission fragments with a total mass of 212 amu and total energy of about 160 MeV. These particles, along with the annihilation products (i.e. pions and muons) will heat the background U238 gas - inserted into the chamber just prior to the release of the antiproton - to one keV temperature. Preliminary analysis reveals that such a propulsion system can produce a specific impulse of about 3000 seconds at a thrust of about 50 kN. When applied to a round trip Mars mission, we find that such a journey can be accomplished in about 142 days with 2 days of thrusting and requiring only one gram of antiprotons to achieve it.},
doi = {10.1063/1.1867173},
journal = {AIP Conference Proceedings},
number = 1,
volume = 746,
place = {United States},
year = 2005,
month = 2
}
  • A thermoacoustic engine is operated within the core of a nuclear reactor to acoustically telemeter coolant temperature (frequency-encoded) and reactor power level (amplitude-encoded) outside the reactor, thus providing the values of these important parameters without external electrical power or wiring. We present data from two hydrophones in the coolant (far from the core) and an accelerometer attached to a structure outside the reactor. Furthermore, these signals have been detected even in the presence of substantial background noise generated by the reactor's fluid pumps.
  • A thermoacoustic engine is operated within the core of a nuclear reactor to acoustically telemeter coolant temperature (frequency-encoded) and reactor power level (amplitude-encoded) outside the reactor, thus providing the values of these important parameters without external electrical power or wiring. We present data from two hydrophones in the coolant (far from the core) and an accelerometer attached to a structure outside the reactor. These signals have been detected even in the presence of substantial background noise generated by the reactor's fluid pumps.
  • The use of antiprotons to initiate the fusion reactions in the Gasdynamic Fusion Rocket (GDFR) is examined as potential replacement of the neutral beam injection system often cited in connection with fusion power reactors. The effectiveness of this approach depends critically, however, on the ability of the antiprotons to penetrate the plasma and reach the center of the engine without undergoing many annihilation reactions along the way. Using expressions for the annihilation rate per unit distance and the stopping power of antiprotons in a fully ionized hydrogenous plasma we calculate the annihilation distribution and the fraction of antiprotons that reachmore » the central region in a relatively cold deuterium-tritium plasma. We apply these results to a rocket engine 16 m in length and containing plasma with 10{sup 16} cm{sup {minus}3} density, and we find that well over 90{percent} of the annihilations take place within a few centimeters from the midplane of the engine when the initial plasma temperature is 20 eV. Under these conditions we find that about 10{sup {minus}5} grams per second of antiprotons injected at an energy of about 4 MeV are required to ignite the plasma in this rocket engine. {copyright} {ital 1996 American Institute of Physics.}« less
  • At the beginning of the development of nuclear power for space, motors and electric-power plants were produced separately: first in the form of nuclear rocket motors (NRMs) with a thrust of 40-100 tonnes (project NERVA in the USA) or about 4 tonnes (project IRGIT in the USSR) and second - reactors for producing 5-100 kW of electric power by means of thermoelectric, thermionic, or turbine machine with a Brayton energy-conversion cycle. Examples are SNAP-100 in the USA and the Topaz reactor in the USSR.