▎ 摘　　要

NOVELTY - The apparatus has a variable inductor for storing a magnetic flux in situ within a cryogenic system configured for a persistent magnetic operation mode. A superconducting magnetic circuit is provided in series with the variable inductor. A persistent magnetic field is measured by a magnetic field measurement device selected from a group consisting of a Hall effect sensor, a super conductive quantum interference device (SQUID), a graphene Hall sensor, and a nuclear magnetic resonance (NMR)-based magnetic measurement probe. The superconducting magnetic circuit and the variable inductor are situated in a cryostat. USE - Apparatus for storage of magnetic flux at cryogenic temperatures for superconducting devices, for stabilization and tuning of persistent currents using variable inductance as alternative to flux pumping. ADVANTAGE - The apparatus eliminates quench and recovery process of a persistent current switch (PCS) to allow for adjustment of magnet current on a fly with short adjustment times and possibility for quick feedback. The apparatus adjusts current of the circuit with minimal use of an external power supply or leads into the cryostat, and transfers current back and forth from a bank to a main coil by simply changing inductance of the bank. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for maintaining a persistent magnetic field in a cryogenic apparatus. DESCRIPTION OF DRAWING(S) - The drawing shows a circuit diagram of an apparatus for storage of magnetic flux at cryogenic temperatures for superconducting devices. 100Flux tuner circuit