TS-2 Instrument Developments
18 Aug 2009



Development at ISIS is a continuous process, driven in response to the changing needs of the user community and to maintain ISIS as a world-class neutron and muon source.

Detector frames in place inside the Nimrod instrument blockhouse

Evolution of existing instruments and design and construction of new ones provide fresh opportunities for materials investigations. Developments over the past year include both first and second target stations.


Nimrod on the Second Target Station will provide access to length scales from the interatomic (<1nm) through to the mesoscopic (>300nm), bridging the gap between small- and wide-angle neutron scattering. Nimrod’s main beam line is essentially complete, with final components available for installation shortly. The blockhouse is constructed and the detector and vacuum tank frames are being installed and aligned. The main vacuum tank has been delivered from Italy. All 60 detector modules are on site, and about half have been tested. Nimrod will be released into the user programme in the first half of 2009.


Testing of Sans2d detector trolleys

Testing of the Sans2d detector trolleys earlier this year
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Small Angle Neutron Scattering (Sans) is able to provide structural information in the nanometre to micrometre range. Using multiple position-sensitive detectors, Sans2d represents a new concept for small angle scattering, giving unsurpassed simultaneous data collection across the entire range of length scales. Construction of the new Sans2d beam line in proceeding well. The five 3 ton steel blocks that swap 2m of guide for 2m of collimation and five 8-position aperture strips have been precision aligned and tested. The large jaws at the front of the tank, trolleys for the two 1m square position sensitive detectors and baffles in the large vacuum tank, plus detector beam stop mechanisms are all now operational.


Inter is the first TS-2 instrument to measure neutrons. The engineering worked hard to prepare the instrument for neutron reception in order to evaluate the performance of the hydrogen/solid methane grooved moderator. This required all the Inter shielding and interlocks to be in place and the guide system to be aligned. Collimation, sample position and detector motion control have been tested, as have the computer interfaces to data collection and beam line alignment. Inter is now in a commissioning phase and we look forward to having a fully scheduled instrument in early 2009.


The Let vacuum tank in position

The 50 tonne Let vacuum tank in position shortly after delivery in January
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Let is the low energy multi-chopper spectrometer that will make use of the high flux of low energy neutrons on the Second Target Station. It will be a highly versatile, high flux machine with a complex arrangement of 7 disc choppers to allow simultaneous collection of many incident energies within a single time frame. The 50 tonne sample tank has now been delivered and is in place, as are the guides, steel work and most of the blockhouse. All the detectors and choppers are here and working, and the project is on track to enable us to start commissioning at the end of 2008.


The past year has seen the installation of straight guides, sample stack and both optic benches on Polref. A test of the motion control software proved the wiring and mechanics of the detector side moveable optics. In the next few weeks Polref should be fitted with its detectors and incident beam polarisation gear in preparation to receive first neutrons in the blockhouse.


The construction of Offspec is nearing completion.  The instrument will be commissioned as a polarised reflectometer by the end of 2008. The spin-echo system designed and constructed by TU-Delft will be installed and tested prior to the instrument receiving first neutrons and is expected to be fully operational early in 2009.

Sample positioning system on Offspec

Ivan Solovej, Christian Mammen (JJ-Xray, Denmark) and Nick Webb (ISIS) installing a sample positioning system on the Offspec reflectometer
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