Cryotron with adjacent paths of superconductor - and material showing magnetic phase transition, allowing operation without destruction

摘要

A cryotron with a first conducting path of superconductive material (I), which is normally conducting on the action of a critical magnetic flux density, has second conducting paths closely adjacent to the first conducting paths and consisting of a material (II) which shows a magnetic phase transition from a state of low magnetisation to a state of high magnetisation of an effective magnetic field of a given field strength in this material. This given field strength is less than the critical magnetic field strength at which the critical magnetic flux density is produced. In the highly magnetised state, the second paths induce a magnetic flux density higher than the critical flux density in the (I) of the first paths. The conducting paths pref. are meander-shaped and can be produced by thin film techniques on a substrate. Used esp. in superconducting cables. The cryoton can be kept below the critical value and can operate without destruction i.e. when it breaks the load current, which alone produces the critical flux density. Also, the first paths change from superconducting to normally conducting along the entire length, rather than in very short stretches, as soon as the second paths assume a state of high magnetisation.