|PROPOSAL NUMBER:||03-II T8.01-9933|
|PHASE-I CONTRACT NUMBER:||NNM04AA93C|
|RESEARCH SUBTOPIC TITLE:||Realistic non-nuclear testing of nuclear systems|
|PROPOSAL TITLE:||Effect of Ambipolar Potential on the Propulsive Performance of the GDM Plasma Thruster|
|SMALL BUSINESS CONCERN (SBC):||RESEARCH INSTITUTION (RI):|
|NAME:||Reisz Engineers||NAME:||University of Michigan|
|ADDRESS:||2909 Johnson Rd.||ADDRESS:||Department of Nuclear Engineering and Radiological Science|
|STATE/ZIP:||AL 35805-5844||STATE/ZIP:||MI 48109-2104|
|PHONE:||(256) 883-2531||PHONE:||(734) 764-7250|
PRINCIPAL INVESTIGATOR/PROJECT MANAGER
U.S. Citizen or Legal Resident: Yes
TECHNICAL ABSTRACT (LIMIT 200 WORDS)
The Gasdynamic Mirror (GDM) thruster is an electric propulsion device, without electrodes, that will magnetically confine a plasma with such density and temperature as to make the ion-ion collision mean free path much shorter than its length, but the macroscopic time scale is smaller than the characteristic time for electron-ion equilibrium. So, the electrons and ions have different temperatures and the magnetic mirror field induces an ambipolar axial electrostatic field which, acting with the nozzle effect of the diverging magnetic field, will accelerate the ions exiting the GDM in a jet along the centerline, giving the thruster a specific impulse that is up to 30 times greater than a comparable device in which the hot propellant is expanded adiabaticallyThe density and temperature ranges and the basic mode of GDM operation mesh well with electric power input by microwaves via Electron-Cyclotron Resonance Heating (ECRH). A combined ECRH/GDM thruster will have an operating envelope that will span the gap (about two orders of magnitude in density) between ion engines and magnetoplasmadynamic (MPD) arc thrusters, without the endurance limitations imposed by electrodes. The proposed research will explore the operational envelope of these thrusters. Experiments have shown that stable operation can be achieved.
POTENTIAL NASA COMMERCIAL APPLICATIONS (LIMIT 100 WORDS)
The GDM is a promising candidate for NASA Mars cargo transportation missions. A GDM thruster, of 1.5 Mwe, using lithium propellant, can produce 42 Newtons thrust at specific impulse of 3500 seconds. Carrying 90 mT of cargo on a one-way mission to Mars, the journey will take 357 days with an initial mass in low earth orbit (IMLEO) of 147 mT using current nuclear electric power system. A comparable MPD thruster with the same input power takes 700 days at an IMLEO of 238 mT. This type thruster, with 100 kWe can be used in other planetary missions.
POTENTIAL NON-NASA COMMERCIAL APPLICATIONS (LIMIT 100 WORDS)
The GDM thruster will be an economical propulsive system for commercial satellite placement and maintenance. Aerospace firms can employ GDM thrusters for planetary cargo transportation missions. With the development of the GDM device into variable high thrust and variable high specific impulse thrusters, manned missions to the outer planets will be feasible. The experimental thruster can be developed for use by aerospace firms for satellite and planetary missions. As advances in this thruster concept are made, terrestrial power systems can be developed. Successful generation of power from ground based GDM devices will help develop non-centralized power generation systems.