Properties of high current superconducting magnet coils

Abstract

In connection with the fabrication of an adiabatic demagnetization cooling device, the properties of some high current superconducting magnet coils have been studied. This thesis includes investigations of critical current vs. magnetic field for Nb(3)Zr coils wound with several packing fractions. The coils were wound bifilar in order that conditions of zero net field could be studies, as well as the properties of single and multiple layers of windings. The problems of connections to the Nb(3)Zr wire and the thermal expansion of the wire were investigated. An experiment was conducted to determine the optimum size current lead for various currents. A design is presented for a magnetic cooling device utilizing the magnet. Techniques have been developed for growing large single crystals or ferric ammonium sulfate alum for use with the device.