Flux Injector for NMR Magnets

Abstract

In circumstances where it is not possible to make perfectly persistent joints, it is not necessary to rework all the joints as a simple flux pump injector could be built with the magnet to stabilize the decay. This is particularly important in the case of NMR magnets where the magnetic field decay is of order 0.01 ppm/hr. This paper describes a flux pump which is used in the first instance to energize a coil to a very high current. In a second stage, the flux pump was used to periodically inject a small incremental current to the magnet and thus stabilize its decay.