Near and InterMediate Range Order Diffractometer
NIMROD is the Near and InterMediate Range Order
Diffractometer designed for the Second Target
Station at ISIS. This instrument will provide
continuous access to length scales ranging from the
interatomic (< 1Å) through to the mesoscopic (>
300Å) and aims to open up major opportunities for
novel and timely science, in areas where the primary
goal is to relate molecular-level structure to the
phase and function of materials.
This unique instrument specification, bridges the
traditional gap between SANS and wide-angle neutron
scattering, by using a common calibration procedure for
all Q-scales. The instrument makes full use of the longer
wavelengths on TS-II, to increase the upper limit of the
accessible correlation length, while also extracting highresolution from the shorter wavelengths.
Key Science Programme
Complex and Confined Liquids
NIMROD will offer many outstanding new opportunities
for the study of complex fluids and solutions, for
example, this instrument will greatly assist us to
understand and control the solvent mediated interactions
that lead to solute association and conformational
changes, and help us to design chemically selective
solvents. NIMROD will provide crucial structural
information on the nanometre length scales that when
combined with the proposed high stability detector
arrays, will open the possibility for routine studies of
ternary and higher complexity molecular mixtures, at
chemically
and
biochemically
relevant
solute
concentrations.
Performance
Resolution of NIMROD
versus SANDALS
C-Number for NIMROD
versus SANDALS
NIMROD TS2
100000
25
20
∆Q/Q [%]
cts/s/cm3V/0.05Å-1
10000
1000
100
Functional and Composite Materials
NIMROD TS2
SANDALS TS1
SANDALS TS1
15
10
5
10
0
1
0.01
0
0.10
1.00
-1
Q [Å ]
10.00
Moderator
Incident Wavelengths
Q-range
Resolution
Total Length
L1, L2
Flight path
Detectors
Beam size
Detector tank
Sample environment
100.00
10
20
30
40
2θ [°]
Coupled cold + water pre-moderator
0.05Å – 10Å
0.02Å-1 – 100Å-1
2θ = 0.5°-10° <10% ∆Q/Q,
2θ = 10°-40° ~ 2% ∆Q/Q.
30m
20m, 1-5.5m
Tapered collimator, adjustable beam aperture
10 x 200 x 20mm in rows parallel to beam,
and over full range of azimuthal angles,
±90°. <0.1% stability required.
30mm wide x 30mm high
Vacuum, no beam windows visible by detectors
Standard, multi-position sample changer.
The proposed instrument specification is ideal for
studying the mesoscopic structure in numerous
composite materials, where nanometre scale particles
are embedded in a solid or liquid matrix as well as
enabling us to probe the important structural correlations
in a wide range of disordered and partially disordered
solid state systems such as optically active glasses,
mechanically and chemically resistant coatings, and
chemically selective molecular storage or reaction
support media.
Phase Behaviour and Nucleation
A particular forte of NIMROD will be its ability to measure
structure with atomic resolution over a wide range of
length scales in the region of a phase transition (liquidliquid
separation,
crystallisation,
metal-nonmetal
transition, magnetic ordering, ionic conductivity in
glasses), as a function of thermodynamic parameters or
composition.