Durham University Superconductivity Group


Durham University Superconductivity Group

Address: Durham University
Physics Department
South Road
Durham City
Co. Durham

Telephone: 00 44 191 334 3520
Fax: 00 44 191 334 5823
E-mail: d.p.hampshire@durham.ac.uk
Web Site: http://www.dur.ac.uk/superconductivity.durham/index.html

Company Categories: Consultancy, Cryogenic Processes, Research and Development

Company Description:

Research Activities

i) Experiments in high-magnetic-fields:
For the best experiments, we combine world-class commercially available equipment with probes that have been designed and built in-house. Commercial cryogenic equipment in-house includes two high-field magnet systems, a fully equipped PPMS system and a He-3 system. In addition, we have built a number of specialist probes for making strain, magnetic, resistive and optical measurements on superconductors. For example, we built an instrument for measuring the strain, magnetic-field and temperature dependant properties of superconductors for use in Durham and at the European high magnetic field facilities in Grenoble, France. Members of the group have published arguably the best JC(B,T,?) data of its type in the world and developed a new theoretical scaling law which successfully combines phenomenological and microscopic theory.
X. F. Lu, S. Pragnell and D. P. Hampshire – Small reversible axial-strain window for the critical current of a high performance Nb3Sn superconducting strand – Appl. Phys. Lett. 91 132512-3 (2007), also published in: Virtual Journal of Applications of Superconductivity, October 1st, Vol. 13 (2007).
D. M. J. Taylor and Damian P. Hampshire – The scaling law for the strain-dependence of the critical current density in Nb3Sn superconducting wires – Supercond. Sci. Tech 18 (2005) S241-S252
Simon A Keys and Damian P Hampshire – A scaling law for the critical current density of weakly and strongly-coupled superconductors, used to parameterise data from a technological Nb3Sn strand – Supercond. Sci. Technol. 16 (2003) 1097-1108
N R Leigh and D P Hampshire – Deriving the Ginzburg-Landau parameter from heat capacity data on magnetic superconductors with Schottky anomalies. Phys. Rev. B. 68 174508 (2003)
C. M. Friend and D. P. Hampshire – Critical current density of Bi2Sr2Ca1Cu2O? monocore and mutifilamentary wires from 4.2K up to Tc in high magnetic fields. Physica C 258 213-221 (1996).
D. N. Zheng, H. D. Ramsbottom, and D. P. Hampshire – Reversible and irreversible magnetisation of the Chevrel phase superconductor PbMo6S8. Phys Rev B 52 12931-12938 (1995).
New Instruments:
A. B. Sneary, C. M. Friend and D. P. Hampshire – Design, fabrication and performance of a 1.29 T Bi-2223 magnet. Super. Sci. and Technol. 14 433-443 (2001).
N. Cheggour and D. P. Hampshire – A probe for investigating the effects of temperature, strain, and magnetic field on transport critical currents in superconducting wires and tapes. Rev. Sci. Instr. 71 4521-4530 (2000).
H. D. Ramsbottom and D. P. Hampshire – A Probe for measuring magnetic field profiles inside superconductors from 4.2K up to Tc in high magnetic fields. J. Meas. Sci. and Tech. 6 1349-1355 (1995).

ii) Fabricating high-field nanocrystalline superconductors:
Members of the superconductivity group in Durham pioneered the discovery of a new class of nanocrystalline superconductivity materials with exceptionally good tolerance to high magnetic field. These materials provide a new paradigm for high-field conductors which has been patented and then published in the premier Physics journals. Equipment in-house includes DSC, DTA, XRD, glove box, a range of milling machines and furnaces as well a HIP operating at pressures of 2000 atmospheres and up to 2000 C. The upper critical field in Chevrel phase superconducting materials was increased from 60 T (Tesla) to more than 100 T and in elemental niobium from ~ 1 T to ~ 3 T. This work has inspired fundamental and applied scientific investigations into nanocrystalline high-field materials where the important length scales for superconductivity are similar to the length scales for the microstructure.

J. Y. Xiang, C. Fleck and Damian P. Hampshire – Bulk nanocrystalline superconducting YBa2Cu3O7-x- J. Phys: CS 97 (2008) 012237.
B. Pusceddu, S. Charlton and Damian P. Hampshire – Nanocrystalline Nb-Al-Ge mixtures fabricated using wet mechanical milling- J. Phys: CS 97 (2008) 012241.
H J Niu and D P Hampshire – Disordered Nanocrystalline Superconducting PbMo6S8 with a Very Large Upper Critical Field. Phys. Rev. Lett 91 027002 (2003) – also published in: Virtual Journal of Applications of Superconductivity, July 15, Vol. 5 2003 and Virtual Journal of Nanoscale Science & Technology, July 21, Vol 8 2003

iii) Empirical, computational and theoretical understanding of superconductors:

The boundaries between the best experiments, analysis and theoretical understanding and advanced computation are increasingly blurred. In addition to experimental work that includes advanced analysis, we have completed computation that provides the first reliable visualisation of how time-dependant-Ginzburg-Landau theory predicts flux moves in polycrystalline materials. This allows us to address why the critical current density in state-of-the-art commercial materials is still 3 orders of magnitude below the theoretical limit.

G. J. Carty and Damian P. Hampshire – Visualising the mechanism that determines the critical current density in polycrystalline superconductors using time-dependent Ginzburg-Landau theory – Phys. Rev. B
G. J. Carty and Damian P. Hampshire – Numerical studies on the effect of normal-metal coatings on the magnetization characteristics of type-II superconductors – Phys. Rev. B. 71 (2005) 144507 – also published in the May 1st, 2005 edition of the Virtual Journal of Applications of Superconductivity.
I. J. Daniel and D. P. Hampshire – Harmonic calculations and measurements of the irreversibility field using a vibrating sample magnetometer. Phys. Rev. B. 61 6982-6993 (2000).

Industrial Themes:
i) The ITER fusion tokamak: The DOE report – The future of science – considers ITER to be the world’s most important large scientific facility to be built in the next 20 years. Approximately one third of the cost is the superconducting magnets which are to be the largest ever built. The $10B ITER reactor which will produce the world’s first self-sustaining fusion plasma.

ii) Energy: Management of energy resources will be one of critical issues in the C21st. Superconductivity will have an important contribution to make to the development of new technologies. Durham university is ideally positioned to play a key role is this area.
Welcome to the New Year!- Supercond. Sci. Tech. 21 (2008) 010201 (2pp).

iii) High field magnets and MRI: There is a industrial need for superconducting materials that carry higher critical current in high magnetic fields to reduce cost. Applications include high-field research magnetic for accelerators such as LHC and MRI medical body scanners where higher magnetic fields equate to better resolution.

If you would like to apply to join the group, you can access the Durham University Physics Department’s initial application form and reference forms at: www.dur.ac.uk/physics/postgraduate/howtoapply/. The application form must be accompanied by a two–page CV . For the superconductivity group to consider your application, on the application form tick the box for ‘Condensed matter Physics’ and under the section ‘specific sub-fields of interest’ insert ‘Superconductivity in high magnetic fields’. Send the forms directly to d.p.hampshire@durham.ac.uk