| Bore diameter (mm) | Temperature range | |
| Pulse-tube top-loader | 100 | 4 K to 673 K |
| Orange and Blue Cryostats, with V or Al tails | 50 and 100 | 1.5 K to 330 K |
| Dilution refrigerator | 50 | down to 50 mK |
| Superconducting magnet 7.5T | 50 | 2 to 300 K |
| Furnaces | – | 18°C to 1000°C |
| Pressure rigs for gas and liquid handling | Please ask your local contact | |
In this section
Iris
Iris is a quasielastic neutron spectrometer designed to measure slow atomic and molecular motions in condensed phases, providing insight into both the rate and geometry of movement. It has been used to study a range of materials, including adsorbed and confined phases, protein dynamics, ionic liquids, polymers and proton conductors.
Instrument scientists
To find out more about each team member, click the + symbol.
Technical information
| Beamline | N6 |
| Moderator | Hydrogen cooled to 25 K |
| Wavelength limiting choppers | Disc choppers at 6.3 m and 10 m |
| Primary flight path | Curved neutron guide, 2.35 km radius; 65 mm (v) x 43 mm (h) cross-section feeding a 2.5 m focusing super mirror guide to the sample |
| Sample position | 36.41 m from the moderator |
| Beam size at sample | 30 mm (v) x 20 mm (h) |
| Intensity at sample | 1x107 n/cm2s at 150 µA ISIS power |
Related resources
Spectrometer specifications
| – | PG 002 | PG 004 | Mica 002 | Mica 004* | Mica 006 |
| Analysing energy (meV) | 1.84 | 7.38 | 0.207 | 0.826 | 1.86 |
| Dynamic range (meV) | -0.4 to +0.4 | 3.5 to +4.0 | -0.02 to +0.02 | -0.15 to +0.15 | -0.4 to +0.4 |
| Resolution (μeV) | 17.5 | 54.5 | 1.0 | 4.5 | 11.0 |
| Angular coverage (°) | 25-160 | – | 25-155 | – | – |
| Q-range (Å-1) | 0.42 to 1.85 | 0.84 to 3.70 | 0.13 to 0.62 | 0.26 to 1.24 | 0.40 to 1.87 |
| Diffraction detectors | 8 3He tubes
at 2θ ≈ 170° Δd/d = 2.5×10-3 d-range (Å) = 1-12 |
– | – | – | – |
*only available with muscovite Mica. Fluorinated mica should be used for Mica 006 and Mica 002
Sample environment
Iris accepts a wide range of sample environments. Two different sample geometries can be used:
- Flat – aluminium alloy cans of 40 mm x 40 mm for powders, liquids or films, with varying thicknesses (0.1, 0.2, 0.25, 0.3, 0.4, 0.5, 1, 2 mm)
- Annular – aluminium alloy cans 50 mm tall for powders, liquids or films, with varying thicknesses (0.1, 0.25, 0.5, 1, 1.5 and 2 mm)
- Annular with gas loading capabilities (please ask your local contact)
Common sample environments
Software
The main software package used to analyse data from Osiris is Mantid, which performs both data reduction and analysis.
Data Reduction involves converting measured time-of-flight (tof) data into S(Q,ω). Operations include:
- Converting from tof to energy transfer (or other units eg. d-spacing
- Summing of spectra into groups and converting from detector angle to Q-value
- Absorption, empty cell and multiple scattering corrections (if necessary)
Data Analysis refers to science-based interpretation of the reduced data. Operations include:
- Fitting quasi elastic peaks using the convolution method
- Calculating peak parameters using Bayesian analysis
- Fitting peak widths to various available diffusion/rotation models
- Performing Fourier Transformation of S(Q,ω) to I(Q,t)
- Fitting scattering functions to various models including stretched exponential decays
Other software for data analysis
MDANSE
Atomistic simulations, particularly molecular dynamics (MD) simulations are increasingly being used for analysis of quasielastic neutron scattering data. MD provides in-depth microscopic interpretation of quasielastic neutron scattering data. Molecular Dynamics Analysis of Neutron Scattering Experiments (MDANSE) is the software available for this analysis.
Recent publications
Our facility supports a broad research programme that generates impact on a national and global scale. Browse through some of the recent research conducted using the Iris beamline.
Instrument reference
All publications and datasets based on experiments using Iris should cite that the data is collected by DOI: 10.5286/isis.instrument.2351. 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.
Reference publication: The design of the IRIS inelastic neutron spectrometer and improvements to its analysers. Physica B 182, no. 4 (1992): 431-440. DOI: 10.1016/0921-4526(92)90047-V.