A perfect crystal diffractometer (PCD) for ultra-high resolution small-angle neutron scattering (USANS) measurements has been in operation at the thermal neutron beam port, BT-5 since 2002. The PCD increases the maximum size of features accessible with the NCNR's 30-m long, pinhole collimation SANS instruments by nearly two orders of magnitude, from ~102nm to 104 nm.
Q-range | 0.0003 nm-1 to ~0.1 nm-1 |
Size Regime | 0.1 μm to 20 μm |
Source | Beam Tube (BT-5) |
Monochromator | Pyrolytic Graphite Premonochromator Followed by a Triple-Bounce Si(220) Monochromator |
Wavelength | 2.4 Å and 6% Δλ/λ |
Flux at Sample | <17,000 neutrons-cm-2-s-1 |
Sample Size | Up to 5 cm high x 5 cm wide x 10 mm thick |
Analyzer | Triple-Bounce Si(220) |
How BT5 USANS Beam Time is Typically Allocated in Each 38 Day Cycle: