SAM
CRG - Small-angle neutron scattering instrument
Guide hall n°1, cold guide H151 |
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Monochromator | |
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Velocity selector (ASTRIUM,) | Δλ/λ ≈ 10 % (FWHM) (at zero rotation angle) |
Incident wavelength | Variable, 3.5 ≤ λ [Å] ≤ 30 |
| Beam monitor (LND, Inc.) | Thin 235U monitor with 10-6 relative efficiency (count rate ≈ 10 kHz at λ = 6 Å) |
Polarization | |
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m = 4 polarizing double-V cavity (SwissNeutronics) | Cross section (height × width) : 30 × 30 mm2 over 1.37 m |
Flipping ratio at sample position | > 100 at λ = 4-8 Å (max. 150 at λ = 6 Å) over a beam with 20 mm diameter |
Collimation | |
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| Beam attenuators | A set of 4 sintered 10B4C + Gd sieves (with identical hole density but different hole diameters), effective attenuation factors ≈ 1970, 550, 120 and 30 |
3 x m = 1 non-polarizing guides (SwissNeutronics) | Cross section (height × width) : 30 × 30 mm2 over 6.5 m |
| Collimator nose | 2 ... 2.5 m (continuously adjustable to accomodate various sample environments) |
Guide-to-sample distances | 2.5, 5, 7 and 9 m (+/- 0.15 m) |
Sample area | |
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| Sample aperture | User-defined, typically up to Ø = 20 mm |
Flux at specimen at reactor power = 54.8 MW & lowest resolution | 6.1 x 107 n.cm-2.s-1 (at λ = 5 Å) |
| Brightness at specimen at reactor power = 54.8 MW & lowest resolution | 4.2 x 1011 n.cm-2.s-1.srad-1 (at λ = 5 Å) |
Typical sample size | 5-15 mm Ø |
| Sample table | x, y, z translations, 2 independent goniometers and rotations |
| Ancillary sample environments |
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Detector | |
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| Detector type | Single panel monoblock 3He position-sensitive detector (ILL) |
Area, pixel size | 640 x 640 mm2, 2.5 x 5 (H x V) mm2 |
Background | ≈ 1.8 Hz on whole detector (electronic noise), ≈ 5 Hz reactor on |
Sample-to-detector distance | 0.75 ... 6.7 m (continuously adjustable) |
Momentum transfer range | 5·10-3 ≤ Q [Å-1] ≤ 0.6 (at λ = 6 Å) Down to 2·10-3 Å-1 at λ = 15 Å Up to 0.96 Å-1 at λ = 3.5 Å |
