A spherical torus nuclear fusion reactor space propulsion vehicle concept for fast interplanetary travel

Assessment of Open Magnetic Fusion for Space Propulsion

“…The cryo-plant mass is therefore given by M cryo = f n P fus (r p /r m ) exp(-(r m -r p )/λ n ) ×10 3 kg/kW ≡ P fus / α cryo (2.12) 2.4.4 Blanket An optimized blanket made by LiH has been proposed in Kulcinski (1987) with a density ρ s in the range 10 3 kg/m 3 (value used by Santarius (1998)) and much less than the values around 10 4 kg/m 3 of the solid and liquid blankets envisaged for a fusion reactor. The associated mass is given by M s = ρ s (1-r p 2 /r m 2 ) V = ρ s (r m 2 /r p 2 -1) P fus /P spec ≡ P fus / α s (2.13) 2.4.5 Auxiliary systems The estimate used in Williams (1998) for the negative neutral beam system correspond to an efficiency of 29% (108MW beam power out of 367MW input power). The total mass is dominated by the 20 sources (2.5t each) which include the filament source, the three stage accelerator and the neutralizer.…”

“…The working fluid to transport heat is typically He. The mass budget for a 400MWe system (20% efficiency) operating with an inlet temperature of 1700K and outlet temperature of 1300K (see Williams (1998)) is about 145t. In Cheung (2004) an efficiency of 40% is used (7MW produced out of an input of 18MW).…”

“…The studies carried out since the late '80s have therefore tried to optimize the fusion performance in order to maximize the specific power. Several concepts have been considered: the high-field tokamak (Bussard 1990), the spherical torus (Borowski 1995, Williams 1998, mirror systems (Kulcinski 1987, Santarius 1988, Carpenter 1992, Kammash 1995b, field reversed configuration (Chapman 1989, Cheung 2004) and magnetic dipole (Teller 1992). These configurations will be reviewed in the context of the discussion of the different confinement systems.…”

Realizing "2001: A Space Odyssey": Piloted Spherical Torus Nuclear Fusion Propulsion

“…Further study will be performed and possibly incorporated into a future upgrade of the Discovery II. Future areas of analysis include: inclusion of preliminary results of the magnetic nozzle simulation and experiment data, examination of new single null open divertor concept, inclusion of CHE analysis, the creation of a 3 He recovery system, incorporation of a lower aspect ratio fusion reactor, and the redesign of the battery bank.…”

Realizing "2001: A Space Odyssey" - Piloted spherical torus nuclear fusion propulsion

“…Third: a conceptual vehicle design incorporating the proposed design philosophies and related results of a recent series of NASA Glenn (formerly Lewis) Research Center (GRC) papers was the next step in the process. 1,2,3,4,5,6 The findings of these earlier papers emphasized that for piloted, outer solar system missions expected within the 21 st century, adequate payload mass fraction (5% to 15%) and multi-month trip times would require specific impulses (I sp ) and specific powers (α) of 20,000 to 50,000 lb f sec/lb m and 5 to 50 kW/kg respectively 1,4,5,6 . It is the judgment of the authors that direct nuclear fusion space propulsion is the leading technology that can reasonably be expected to offer this capability.…”