WITHDRAWN: Magnetospheric Shielding of Spacecraft and Crew From Galactic Cosmic Radiation

An optimal magnetic shielding configuration for significantly reducing astronaut exposure to Galactic Cosmic Radiation (GCR) on long interplanetary missions has been realized, and is referred to as the Magnetospheric Dipolar Toroidal Magnetosphere (DTM). This configuration was shown to have the singular ability to deflect the vast majority of the GCR including High Z Energetic (HZE) ions. This external (to the spacecraft) dipolar field is created by an array of unidirectional toroidal High Temperature Superconductor (HTSC) windings mounted externally on the surface of the toroidally-shaped spacecraft habitat. In this way the spacecraft directly supports the magnetic hoop forces generated by the toroidal currents and thereby significantly reduces the structural mass requirements for the shield. The magnitude of the toroidal currents are arranged poloidally to flow so as to maintain the spacecraft shell as a constant flux boundary where the magnetic flux is zero thereby keeping the spacecraft habitat field-free. As the dipole magnetic field is perpendicular to the spacecraft habitat in all directions, the DTM provides a deflecting shield to all the incoming GCR which is nearly isotropic. In addition, the DTM shields the HTSC magnets as well thus eliminating the secondary particle irradiation hazard, which can dominate over the primary GCR for shields with closed magnetic topologies. With DTM shielding it was found that both the structural and magnet mass as well as power requirements were significantly reduced. A 3-D relativistic particle code was used to evaluate shielding effectiveness for the GCR spectrum encountered in space. Four topics that will be covered involve a direct comparison of the three principal efforts developed to date for shielding; They are: (1) Effectiveness of the magnetic shielding (2) Issues with secondaries; (3) Launch and space assembly, and (4) Advantages and other uses.