Research communities focused on physical and life sciences require high magnetic fields to study new areas of materials research, nanotechnology, nanoscience and bioscience.
This not only leads to breakthrough innovations through the identification of next-generation materials, but also allows analyses at the nano scale.
High fields, along with low temperatures, are also important to analyze, change and control the required new states of matter. This facilitates real applications, such as nuclear magnetic resonance (NMR), magnetic resonance imaging (MRI) scanners, electron spin resonance (ESR) spectrometers, and standard magnet systems, such as energy generation and high energy physics.
Superconducting magnets can provide high magnetic fields without consuming significant amount of power. They also eliminate the need for the large infrastructure required by resistive magnets. Thanks to their unique physical properties, when superconductors are cooled to ultra-low temperatures, they can carry large electrical currents with no electrical resistance.
At Oxford Instruments, latest advancements in superconducting coil engineering and wire manufacture are giving way to revolutionary design changes in products that are used in a variety of applications, including compact high field magnets.
The Germany-based Dresden High Magnetic Field Laboratory (HLD) is an institute of the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) that performs modern materials research in high magnetic fields.
HLD houses a pulsed magnetic field facility for global scientists. In addition to this, they also carry out investigation into both the function and structure of contemporary materials using high magnetic fields. In order to serve diverse users, HLD needed a high field magnet system to develop even higher field superconducting magnets, and to analyze the materials’ high field magnetism.
However, two issues had to be resolved in the design and development of next-generation of superconducting magnets. These issues were the stresses that exist in the magnetic coils, and the control of large stored energy inside the magnet.
The development of high field, wide bore superconducting magnets, regained dealing with thermal and electro-mechanical challenges. The energy stored in such a superconducting magnet at its full field is relatively large — 5.7 MJ in this example.
If the magnet loses its superconductivity, this so-called energy is dissipated within a matter of seconds. For sake of comparison, this is rougly equivalent to the stored energy of a Volvo FH 550/610 truck tractor that weighs 9.68 metric tonnes travelling at 77 mph.
Oxford Instruments was able to develop and deploy a high field superconducting magnet system at HLD. This compact magnet operates at 4.2 K and produces 19 T within a 150 mm bore. It is capable of housing a range of sample configurations, and even accommodates insert coils for providing higher fields.
This new magnet system represents a major advancement in superconducting magnet technology for research applications, because previously, in order to realize such high magnetic fields, the magnet would have had to be super-cooled to 2.2 K by applying more refrigeration to the liquid helium and needed to be large and expensive to operate.
HLD is already using several Oxford Instruments’ superconducting magnet systems in its research, including the high field 22 T, 52 mm bore research magnet that operates at 2.2 K. The successful completion of the latest product demonstrates how Oxford Instruments works with its customer base during the initial phase of product development.
High-performance re-stacked rod process (RRPTM) low temperature superconductors (LTS) Niobium Tin (Nb3Sn) and NBTI wires were used to create the 19T magnet. Oxford Superconducting Technology, part of the Oxford Instruments group, developed and supplied these wires.
In order to meet the desired specifications, the magnet contains four concentric RRPTM coil sections enclosed by two sections using Niobium Titanium (NbTi) superconductors. These sections are joined in series to work at a single current.
The engineering team at Oxford Instruments successfully resolved a number of technical issues, including processing of bulk RRP coils, control of high stressed coils, and management of large amount of energy stored inside the magnet under quench conditions in a compact environment.
This information has been sourced, reviewed and adapted from materials provided by Oxford Instruments Nanoscience.
For more information on this source, please visit Oxford Instruments Nanoscience.