Potential fabrication method of superconducting multifilament wires of the A-15 type

Abstract

A method is described for production of A-15-type multifilament superconductors, based on mechanical size reduction of composites of unalloyed copper with niobium or vanadium cores. These cores are in themselves hollow and filled with fine grain size powder of an intermetallic compound of niobium or vanadium, rich in the second element of the required superconductor. After obtaining the final dimensions of the ductile composite without intermediate heat treatments, metal and intermetallic compounds are converted by heat treatment into the superconductor wbich is formed as a continuous layer inside the tublets. In particular the preparation is reported of V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> Ga and V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> Si conductors using V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> Ga <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</inf> and VSi <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> powder respectively. Critical current density values of seven filament wire are included, measured at 4.2 K up to 10 T.