Magnet technology and conductor design with high temperature superconductors

Abstract The implications of high temperature superconductors for the design of magnets and conductors are explored. Presuming that a sufficient current density is attained in the superconductor, rules are given to obtain the amount of normal conductor and structural material, which are both essential components in a conductor for use in a magnet system. It is shown that the empirical relation j eff 2 E 0 ≤ 10 23 J A 2 m −4 , linking effective current density j eff and stored energy E 0 , naturally emerges from the requirements of sufficient mechanical strength as well as safe energy extraction in the case of a quench. In the superconductor a j c of 10 5 A cm −2 is sufficient for most purposes. As an alternative to cooling to 77 K in liquid nitrogen we also consider operation at 27 K in liquid neon.