First neutrons to Larmor!
20 Mar 2014



The Larmor instrument, the first of a second phase of instruments to be commissioned on Target Station 2 at ISIS has received first neutrons today.

First monitor spectrum on Larmor with the choppers set up

This is a major milestone for the instrument, which expects to be available for users from next year. Larmor will be a multi-purpose instrument for small angle neutron scattering (SANS), diffraction and spectroscopy, taking advantage of the Larmor precession of polarised neutrons. The completion of Larmor expands the capacity of ISIS to support the SANS community, which encompasses soft matter, complex fluids, food science, bio-materials and pharmacy, advanced materials engineering, environmental and earth science.​

Larmor is the first polarised SANS instrument to be built at ISIS, and will offer measurements across the full length range from atomic and molecular through aggregates to a few microns, and will be able to detect changes in length scales from 10-6 m down to 10-15 m.

Rob Dalgliesh is the instrument scientist for Larmor. He says, “I’m delighted that we’ve successfully seen first neutrons on Larmor – this is a major milestone for us and will enable us to ensure that the instrument is ready to perform its first experiments with users early in 2015.There are several significant challenges ahead – for example this is the first instrument to be built at ISIS that will use EPICS instrument control software and a new version of the data acquisition electronics (DAE3) – but we are well on the way.”

Larmor will accept its first proposals in the October 2014 round with first experiments during April 2015. Initially Larmor will be used for SANS and polarised SANS measurements. The TU-Delft will deliver the equipment required for Spin-Echo SANS in mid 2015. This technique will then become available to the user program in late 2015. Further spin-echo techniques such as Larmor Diffraction, MIEZE spectroscopy, TOFLAR and traditional inelastic neutron spin-echo are proposed by TU-Delft but do not yet have a fixed time scale for delivery. 

‘It’s very pleasing to see the dedication and commitment of the ISIS team rewarded with first neutrons on Larmor. We can now move confidently to instrument commissioning and continue our work to bring the remaining three instruments and reflector change into operation.’ said James Treadgold, the project manager for the phase II development.

The spin-echo equipment for Larmor will be developed in collaboration with TU-Delft, who have delivered similar equipment for OffSpec. As part of the project the Netherlands user community will receive access to 30 days of beamtime a year on Larmor for the next 10 years.