LoQ

LoQ is currently not included in the main ISIS user program. It is used for XPress measurements and equipment testing and commissioning. Special requests can be made to use the instrument for testing in discussion with ISIS management.

LoQ is a fixed geometry Small Angle Neutron Scattering (SANS) instrument with a ~4m incident flightpath and sample-to-detector distance. It has a pair of detectors that enable it to cover a simultaneous q range of 0.006 – 1.4 Å^-1. This enables the instrument to study a wide range of length scales in a broad range of materials including colloids, nanoparticles, polymers, biomolecules, alloys, composites and porous systems.

The instrument views the ISIS Target Station 1 hydrogen moderator through a soller bender and can operate at either 25 or 50 Hz. The incident collimation is determined by a fixed aperture selector, located just before the wavelength-defining disk chopper and the final collimation aperture placed just before the sample. A third aperture, located at the entrance to the sample area, may be used to collimate the beam for transmission measurements.

The main detector is a ³He-CF₄-filled ORDELA area detector 15.15m from moderator with an active area is 64 x 64 cm and 5 x 5 mm pixels. The high-angle detector is an annular scintillator detector located 11.6 m from moderator.

The sample position is ~11.1 m from moderator. Crane access is possible (SWL 1000 kg). Experiments requiring magnets, furnaces and other complex sample environment are performed on the ISIS Target Station 2 instruments. LoQ will only operate sample changer experiments or other measurements where straightforward and compact equipment can be used requiring minimal support-team resources.

While the instrument is not currently part of the main ISIS program, it is used for XPress sample measurements, testing of new equipment and education.