Development of the Superconducting Outserts for the Series-Connected-Hybrid Program at the National High Magnetic Field Laboratory

Abstract

The National High Magnetic Field Laboratory (NHMFL) has embarked on an innovative program to develop a number of Series-Connected-Hybrid magnetic systems. In this novel concept, a set of resistive coils (insert) and a set of superconducting cable-in-conduit conductor (CICC) coils (outsert) are electrically driven in series, rather than independently as in previous hybrid systems. Presently NHMFL is working on 3 different projects. The first, funded by the National Science Foundation (NSF) with an $11.7 million grant, is related to the construction of a cylindrical-bore Series-Connected Hybrid (SCH), for high field nuclear magnetic resonance (NMR), condensed matter physics, biology and chemistry, to be located at the Magnet Lab's Tallahassee location. The second, funded by the Hahn-Meitner Institute (HMI) in Berlin, relates to the engineering design for a horizontal bore Series-Connected Hybrid to be used in a neutron diffraction experimental system. Finally, the third, also funded by NSF, is a conceptual and engineering study for an SCH that would be used for neutron scattering experiments at Oak Ridge National Laboratory's Spallation Neutron Source (SNS), similar to the HMI version. Because of the main points in common between the 3 different systems, our final goal is to develop a superconducting magnetic system suitable for the 3 applications. We believe this is possible for the magnet although, due to the different field/bore orientations, some differences in the mechanical design of the cryostat and resistive inserts will exist. In this paper we will give an overview of the R&D strategy devised to develop these superconducting magnetic systems, together with a report on the present status of such program.

Cable-in-conduit conductors: lessons from the recent past for future developments with low and high temperature superconductors

“…The strategy developed here to tackle the issue of performance degradation is very clearly and logically discussed in [7]. It is based on three main points: a careful and critical analysis of previous results, including those of the EDIPO CICC; the development of a mechanical computation code, to support design choices; manufacture and systematic testing of a minimum set of CICC samples with different features in terms of [116]: (a) VF (30% or 40%); (b) cable layout (either based on a triplet at first cable stage, or on a 6-around-1 cable stage); (c) twist pitch sequence (either short or relatively LTP); (d) jacket material (316 LN or Haynes 242).…”

“…As a matter of fact, some of the advantages of this concept have been exploited also in different environments, and CICC solutions have been adopted to build or design magnets for test facilities [2][3][4][5] or for very high field (HF), hybrid magnets, characterized by large stored energies [6][7][8][9][10]. In the Swiss facility SUpraLeiter TestAnlage (SULTAN) [11], built in the late seventies, and representing the reference facility presently available for tests of high current (up to 100 kA), HF (up to 12 T), forced flow large size conductors, the magnetic field is itself generated by three pairs of split coils cooled by forced flow of supercritical helium.…”

HFM/EXED: The High Magnetic Field Facility for Neutron Scattering at BER II

“…As a result, the inner resistive coil provides a conical bore at each end to allow neutron-scattering to detectors up to ±15°o the eld axis. The superconducting coil is a 13-Tesla, 500-mm cold bore coil consisting of Nb 3 Sn cable-in-conduit conductor (CICC) and weights 5 tons (6 tons full cold mass including anges, joints and piping) (Bonito Oliva et al, 2008;Dixon et al, 2009Dixon et al, , 2010. The magnet central bore is horizontal so that it can align with the neutron beam axis.…”

First Hybrid Magnet for Neutron Scattering at Helmholtz-Zentrum Berlin

“…4 shows the sample surrounded by the two radiation 3OrCB_01 shields and the vacuum container sitting in the room temperature bore of the magnet. The cryostat provides sample temperatures down to about 0.5 K from two pumping stages for liquid 3 He and 4 He. A pulse tube machine is used for precooling in the higher Kelvin temperature range.…”

“…Neutron scattering in high magnetic fields has led to a number of important discoveries such as Bose-Einstein condensation in magnetic materials and field induced antiferromagnetic order in high temperature superconductors [1], [2]. However, research of condensed matter systems is bringing up an increasing number of questions which require experiments combining neutron scattering and magnetic fields above 17 T. Therefore HZB started in collaboration with NHMFL an ambitious project of extending the magnetic field range significantly [3], [4]. One should mention that DC fields are essential for neutron scattering experiments, especially for those samples which need large data sets for good statistics.…”