V1
Membrane Diffractometer
Instrument description
The design of the instrument is dedicated for biological samples or other samples with large unit cells (5 -10 nm in cell length). The vertically focusing graphite monochromator provides adjustable wavelengths between 0.4 nm and 0.6 nm, making use of the full cross section of the neutron guide (3 cm wide, 12.5 cm high). A movable Be-filter at liquid nitrogen temperature may be used to suppress second order wavelengths below 0.39 nm. If less stringent collimation conditions allow, high flux at short monochromator - sample distances (approx. 80 cm) are made possible by a compact construction of shieldings. Sample and detector supports are movable on aircushions. The maximum Q value in all configurations with Be-Filter is limited to 22 nm-1.
Applications
The instrument is designed for experiments with biological membranes, polymers, microemulsions, micelles and other partly oriented systems. The high spatial resolution of the detector is appropriate for studying reflections from biological single crystals and magnetic satellite reflections.
Selected examples
Interaction of β-amyloid with lipid membranes
| Instrument Data | |
|---|---|
| Beam tube | NL 1A |
| Collimation | α0 = 1° at 0.45 nm (resulting from the 58Ni-neutron guide) α1: defined by two slit systems |
| Monochromator | PG (002), vertically focusing |
| Take off angle of monochromator | 2ΘM = 60°-120° (not alterable during experiment) |
| Wave length | λ = 0.4-0.6 nm |
| Flux | 1 x 107 n/(cm2 s) |
| Range of scattering angles | -10° < 2Θ > 120° |
| Angle resolution | |
| Range of lattice spacing | |
| d resolution | |
| Sample size | |
| Detector | 3He, 19 x 19 cm2 pixel size 1.5 x 1.5 mm2 height and inclination adjustable |
| Polarized neutrons | no |
| Instrument options | |
| Sample environment | Special sample containers with humidity and temperature control |
| Software | CARESS with special features for area detector and powder diffraction data evaluation |
| Monochromator/sample distance | 0.8 m - 1.5 m (extendable) |
| sample-to-detector distance | 0.8 m - 2.0 m, 1.0 m standard |