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?6K?1, preferably ?sheet<8*10?6K?1, an elastic limit Rp0.

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.

Abstract: A device for generating a high level electron current pulse includes a housing whose interior can be evacuated from outside the housing, a cathode electrode located in the housing and arranged to be connected to a high voltage generator, an anode electrode disposed in the housing in facing relation to the cathode electrode, the anode electrode having an opening aligned with the electron emission portion of the cathode electrode and being provided with a grid which covers this opening and which presents a high electron transmission level, the grid defining a plane with one face of the anode electrode, and the walls of the housing defining an annular space filled with a solution whose resistivity is a function of its concentration to give these walls a variable electrical resistance which can be adjusted to match the impedance of the cathode electrode - anode electrode system to that of the high voltage generator.