A self-supporting flexible thermal radiation shield

A self-supporting flexible shield for location between a warm surface and a cold mass which comprises a shaped plastic sheet with a low emissivity coating on both sides. Preferably, the flexible shield is for use in superconducting magnets 10. The flexible shield may comprise a sheet or shell 24 of polymer with aluminium on both sides wherein the thickness of the layers is 20-100 nm. The sheet of polymer preferably comprises a sheet of PET (polyethylene terephthalate) with a thickness of 125-500 µm. Preferably, the flexible shield thermally floats at a temperature intermediate between a temperature of the cold mass and a temperature of the thermal radiation shield. Preferably, the superconducting magnet comprises and/or a folded structure, a folded box cover and a folded cowl of the shaped plastic sheet with a low emissivity coating on both of its sides attached to the cold mass. Preferably, the folded structure comprises a slit and barbed tab arrangement 26.