Abstract: An arrangement for testing an elongated body 1 or a welded and bonded joint in the body for faults 60 has a device 4, 5 for production of an eddy current in the elongated body 1 or its welded and bonded joint. At least one magnetic field sensor 7 for sensing the magnetic field is provided on the elongated body 1 or the welded and bonded joint. The dimensions of the at least one magnetic field sensor 7 are equal to or less than the fault 60 to be investigated.

Abstract: A multifilament superconductor (1) has a core area (2), several superconductor filaments (7) and reinforcement filaments (6). The superconductor filaments (7) and the reinforcement filaments (6) are arranged, so that they have a regular two-dimensional matrix (5) in the cross-section of core area (2). The reinforcement filaments (6) consist of tantalum or a tantalum alloy, and the superconductor filaments (7) each have a core (8), made from a powder metallurgically produced superconductor, which is enclosed by an inner shell (9), made of a non-superconducting metal or a non-superconducting alloy. The core area (2) is enclosed by an outer shell (3), made of a non-superconducting metal or a non-superconducting alloy.

Abstract: An arrangement for testing an elongated body 1 or a welded and bonded joint in the body for faults 60 has a device 4, 5 for production of an eddy current in the elongated body 1 or its welded and bonded joint. At least one magnetic field sensor 7 for sensing the magnetic field is provided on the elongated body 1 or the welded and bonded joint. The dimensions of the at least one magnetic field sensor 7 are equal to or less than the fault 60 to be investigated.

Abstract: A superconductor element comprising Nb3Sn, in particular, multi-filament wire, which contains at least one superconducting filament (1) which is obtained after drawing through solid diffusion reaction from an initial filament structure which comprises a longitudinal hollow tube (3) of niobium (Nb) or an Nb alloy, in particular, NbTa or NbTi, with an inner surface (8) and an outer surface (9), wherein the tube (3) is embedded into a thermally and electrically highly conducting metal matrix (2), in particular, of copper (Cu), wherein the tube (3) is filled with a material (4) which contains tin (Sn) is characterized in that, for mechanical reinforcement of the conductor element and as a diffusion barrier during solid diffusion reaction, the outer surface (9) of the tube (3) is directly and completely surrounded by a sleeve (7) made from a metallic material which has, at room temperature, a thermal expansion coefficient ?sheet<17*10?6 K?1, preferably ?sheet<8*10?6 K?1, an elastic limit Rp0.