Instrument Description

Guide hall 1, thermal guide H22

monochromators
typedouble-focusing bent Si-crystal monochromator
dimensions209 x 170 x 12 mm3
wavelength range1.3 - 3 Å
variable take-off55° - 125°
horizontal curvature radius2.68 m
vertical curvature radius1.5 m - ∞
sample stage
hexapod
max. load
500 kg
workspaceother data
translation x,y± 300 mmmax. distance to beam460 mm
z150 mm
rigid translation700 mm
tlit (χ, φ)± 30°rigid rotation (Ω)360°
rotation (ω)± 45°   
beam defining optics
primary slit :
apertures
computeur controlled
0.3 mm - 5 mm horizontal
manual (fixed)0.3 mm - 50 mm vertical
distance to gauge volume0 - 600 mm, motorised
secondary slit :
apertures
computer controlled
0.3 mm - 5 mm horizontal
manual25, 50 mm vertical
distance to gauge volume0 - 200 mm, motorised
radial collimators
primary and secondary
focus (full width at half maximum)
0.6 mm and 2 mm (horizontal and vertical)
distance to gauge volume150 mm, 380 mm, 420 mm
oscillation± 1°
detector
type2-dimensional Position Sensitive microstrip Detector
active area80 x 80 mm2
readout256 x 256 channels
angular step0.02° (at 1 m sample-detector distance)
distance to gauge0.5 - 1.5 m

SALSA is a diffractometer which enables the measurement of internal strain (residual and applied) in engineering materials. The instrument uses a monochromatic beam and a Position Sensitive Detector (PSD), which covers 4° in 2θ at a typical distance of 1 m from the sample.


Sample dimensions can vary from a few millimetres to over a metre. The sample stage is a 6-axis ‘hexapod’ which is able to support samples of over 500 kg and perform complicated spatial scans. A 360° rotation (omega) is available around a vertical axis through the ˝gauge volume˝. To assist sample alignment and programming of complex scans, SALSA makes use of the Coordinate Measurement Machine (CMM) of the ILL-ESRF material science support laboratory.


Two options for beam size definition are available: computer controlled variable slit systems and radial focusing collimators. The primary and secondary slit systems allow beam size variations between 0.3 mm and 5 mm horizontally and up to 25 mm vertically. A range of collimators are available with foci as small as 0.6 mm (FWHM) and a fixed distance to the gauge volume of 150 mm. Collimators are particularly useful for high spatial resolution measurements near interfaces, surfaces or in coatings, since they give lower surface aberrations.


The neutron beam is delivered via a double focusing monochromator composed of 39 silicon variably bent crystals, each 5 mm high, 170 mm long and 12 mm thick. Its total height is 209 mm, corresponding to the guide dimensions (30 × 200 mm). Thanks to phase space focusing, it takes advantage of the beam divergence provided by the neutron guide and supplies the high resolution needed for strain determination. Changing the horizontal curvature and/or the take-off angle allows the use of high-intensity or high-resolution configurations. The optimum neutron flux is at λ = 1.66 Å, which is ideal for a many typical of engineering materials.


Two in-situ (and offline) stress rigs are available a 5 kN vertical/horizontal mounting machine for small samples and a 50 kN horizontally mounting machine for static or dynamic (fatigue) tests.