MERLIN
MERLIN is a very high count rate spectrometer optimised to study dynamics in single crystal samples. Its energy scale is ideally suited to the physics of everyday life. It has made significant contributions to our understanding and exploitation of high temperature superconductors, solar cells and functional magnets.
Instrument scientists
To find out more about each team member, click the + symbol.
Technical information
| Beamline | S4/5 |
| Moderator | 300K dedicated water moderator centrally poisoned with Gd |
| Neutron guides | Supermirror converging m3 guides |
| Incident energy | 10-180 meV |
| Energy resolution | Depends on the choice and speed of Fermi chopper. Δhω/Ei=4-7% FWHM at the elastic line |
| Primary flight path | 11.8 m |
| Secondary flight path | 2.5 m |
| Fermi chopper | 10 m from the moderator. 50-600 Hz phased to ISIS pulse ±0.1 ms Gd chopper package enables operation in RRM mode, but places upper limit of 180 meV on incident energy. |
| Background chopper | 8.5 m at 50 Hz |
| Sample position | 11.8 m from the moderator |
| Beam size at the sample | 30 x 50 mm. Motorised jaws can define a smaller beam size. For larger samples please discuss with instrument scientists. |
| Detectors | 2.5 m from the sample position. Position sensitive 3He tubes (10 bar partial pressure) 2.5 cm diameter, 3 m long, resolution 21 mm along the tube. Angular range: -45° to 135° horizontal; ±30° vertical direction. Smallest scattering angle 3°. |
| Intensity at the sample (Ei= 45 mev, Δhω/Ei=5%) | 6x104 ncm-2 s-1 |
| Detector pixels | 69632 |
| Solid angle (Sr) | 3.1 |
| Sample enviroment | Accepts all standard sample environment. Instrument tank constrains maximum magnetic field available: - 2 T in 7.5 T standard magnet |
Related resources
Technical overview
Merlin has been in user operation since 2008. Its design exploits recent advances in technology with a supermirror guide to enhance flux, as well as 3 m-long position-sensitive detectors in a vacuum, making it idea for the study of single crystals.
The detector bank covers a massive π steradians of solid angle with an angular range from –45o to +135o in the horizontal plane, and ±30o in the vertical plane. This allows large swathes of Q, ω space to be accessed in a single run.
Since 2014, Merlin has been running in event mode, and by using a Gd chopper combined with a disk chopper, it is able to run in repetition-rate multiplication (RRM) mode, allowing users to simultaneously measure with several incident energies between 10 meV and 180 meV.
Sample environment
Merlin has top-loading CCR operating in the temperature range 6 – 575 K, an orange cryostat operating in the temperature range 2 – 300 K and a dilution fridge operating in the temperature range 0.1 – 4 K.
Recent publications
Instrument reference
All publications and datasets based on experiments using Merlin should cite that the data is collected by DOI: 10.5286/isis.instrument.9632. Experiment DOIs follow the format 10.5286/ISIS.E.RBXXXXXXX, where XXXXXXX is the 7-digit experiment (RB) number and these can be viewed via the Data Gateway.