A payload to test in space Superconductive Magnetic Shielding technology R. Battiston Perugia University June 2010

The radiation magnetic shields which have been proposed all have a toroidal (confined field) geometry The three proposals found in the literature have an estimated volume/mass as described in the following table 1)Hoffman et al 2)Choutko et al 3)Spillantini et al

264_2f/3 y05K004bV1 It is much smaller than the existing Cern magnets. Crew compartment 7.00 m 6T Example based on Existing AMS-02 Technologies Mars Magnet System – (Choutko et al) 3T Superfluid helium vessel Thermal radiation shields Barrel toroid supports End Cap toroid supports 1.00 m Propulsion, Energy and Live support, Ø m Ø 4.50 m

Upper limits for the total mass of a magnetic shield can also be derived from the actual values of the total mass of the large ATLAS toroidal systems at CERN - LHC (1000 t), since a scaled down version of ATLAS (all dimensions reduced by a factor of 2) would already have the magnetic properties required for a spacecraft radiation shield (however not optimized for space !).

The ATLAS Superconducting Barrel Toroid at CERN

Proposed payload Proposal to develop a SC toroidal magnetic system with volume/weight with respect to toroidal magnetic shield design being considered ( t) or with respect to large toroidal magnetic systems built at CERN (1000 t) The magnet will be equipped with small solid state radiation detectors to measure the radiation inside and outside the magnetic system plus telemetry electronics  < 100 kg total mass

264_2f/8 Scaled down version of ATLAS toroids (1/22 linear, volume) Diameter 18 m  0,8 m Length 25 m  1,13 m Volume/mass  = t  100 kg

The interest of this payload would consist in the following 1)Develop at a scaled down version of the various technologies needed for a radiation shield for space explorations: structural mechanics, vacuum, He recirculation, cryogenics and thermal insulation, electrical, operations…. 2)Measurement of the shielding performances in actual deep space environment 3)Study the radiation resistance of SC wires exposed to significant doses of radiations: in the literature the radiation hardening of SC wires has been shown to improve the performances and the stability of superconductors: 1)Effect of Fast Neutron Irradiation on the Properties of a Superconducting (Bi % 238U)/Ag-Tape Goncharov, I N et al., Dubna, 23 Apr 2001, JINR-P Goncharov, I N 2)Enhancement of the high-magnetic-field critical current density of superconducting MgB2 by proton irradiation, Y. Bugoslavsky et al., Nature 411, (31 May 2001) |

THANKS !