The Gasdynamic Mirror Fusion Propulsion System -- Revisited

Journal Article · Sun Feb 06 04:00:00 EST 2005 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.1867169· OSTI ID:20630580

Kammash, Terry ^[1]; Tang, Ricky ^[2]

---

1. Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Blvd, Ann Arbor, MI 48109 (United States)
2. Department of Aerospace Engineering, University Michigan, 1320 Beal Ave, Ann Arbor, MI 48109 (United States)

Many of the previous studies assessing the capability of the gasdynamic mirror (GDM) fusion propulsion system employed analyses that ignored the 'ambipolar' potential. This electrostatic potential arises as a result of the rapid escape of the electrons due to their small mass. As they escape, they leave behind an excess positive charge which manifests itself in an electric field that slows down the electrons while speeding up the ions until their respective axial diffusions are equalized. The indirect effect on the ions is that their confinement time is reduced relative to that of zero potential, and hence the plasma length must be increased to accommodate that change. But as they emerge from the thruster mirror - which serves as a magnetic nozzle - the ions acquire an added energy equal to that of the potential energy, and that in turn manifests itself in increased specific impulse and thrust. We assess the propulsive performance of the GDM thruster, based on the more rigorous theory, by applying it to a round trip Mars mission employing a continuous burn acceleration/deceleration type of trajectory. We find that the length of the device and travel time decrease with increasing plasma density, while the total vehicle mass reaches a minimum at a plasma density of 3 x 1016 cm-3. At such a density, and an initial DT ion temperature of 10 keV, a travel time of 60 days is found to be achievable at GDM propulsion parameters of about 200,000 seconds of specific impulse and approximately 47 kN of thrust.

• OSTI ID: 20630580
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 746; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ACCELERATION
CONFINEMENT TIME
ELECTRIC FIELDS
ELECTRONS
ION TEMPERATURE
ION THRUSTERS
IONS
KEV RANGE
LENGTH
MAGNETIC MIRRORS
PERFORMANCE
PLASMA
PLASMA CONFINEMENT
PLASMA DENSITY
POTENTIAL ENERGY
PROPULSION
PROPULSION SYSTEMS
PULSES
SPACE VEHICLES