Oxford
Instruments has collaborated with two World-class neutron scattering facilities,
the ISIS Neutron Source (STFC Rutherford Appleton Laboratory, Didcot) and the
ILL neutron facility (Institut Laue-Langevin, Grenoble) to deliver the first
high field helium recondensing magnets.
Recondensing dewars use a cryocooler to capture evaporated gas and turn it
back into liquid helium. Using recondensing technology considerably decreases
the helium consumption of these magnets while enabling the stringent magnet
designs required by neutron scattering applications. These highly complex magnets
are good examples of how researchers and industry can work together to push
technological boundaries.
The ILL received a 10 T asymmetric split pair coil magnet for their three-axis
spectrometers. Dr Eddy Lelièvre-Berna, Advanced Neutron Environment Team
Leader at ILL, commented: “With this new design, the superconducting coils
are reliably maintained at low temperature within a liquid Helium bath while
considerably reducing the boil-off. Compared with dry systems, the absence of
room-temperature bore provides a much larger sample space. It also reduces the
amount of material in the beam and avoids unwanted neutron absorption and neutrons
scattered to the detectors. Together, we have really made a step forward. Among
the many topics to be investigated with this magnet are multiferroic properties,
quantum phase transitions and excitations in single-molecule magnets. Our satisfaction
is such that we have decided to order another magnet for studying the magnetic
substrates of our future hard disks.”
The ISIS Neutron Source purchased two recondensing neutron scattering magnets
including a 9 T wide angle and 14 T at 4.2 K. These magnets will be used on
the Let, Merlin and Wish instruments at ISIS. Dr. Oleg Kirichek, Sample Environment
Group Leader at ISIS, Rutherford Appleton Laboratory commented: “Having
a recondensing system allows us to considerably reduce our helium cost and health
and safety issues. It also provides a homogeneous temperature distribution,
which is crucial for optimum magnet performance. With these magnets, we should
be able to provide our users with high magnetic field sample environments for
neutron scattering experiments in a number of research areas such as high temperature
superconductors, quantum magnets, spintronic materials, spin frustrated systems,
heavy fermions, nanomagnetic materials and the recently discovered iron-based
high-temperature superconductors.”
Dr John Burgoyne, Manager of the Magnets Business Group at Oxford Instruments
says: “Working with ILL and ISIS gave us access to some of the world’s
leading neutron scientists. Their knowledge and expertise in neutron scattering
was crucial to the successful delivery of these innovative systems. It has also
enabled us to expand our knowledge and develop a new system that we can offer
to other facilities.”