D33 - Massive dynamic q-range small-angle diffractometer
For materials science and physics studies, the usual array of sample environments, e.g. electromagnet, cryostat, cryomagnet and furnace, can be mounted easily on D33. The generous sample space can accommodate bulky and massive sample environments such as large cryomagnets, e.g. the 17 T cryomagnet belonging to the University of Birmingham, as well as 3He spin analysis setup.
D33 - Massive dynamic q-range small-angle diffractometer
D33 is a Small-Angle Neutron Scattering instrument for the characterization of samples with typical sizes varying from the nanometer scale to few tenth of micrometer. In addition to a standard monochromatic mode of operation, D33 offers a time of flight mode (TOF) to cover an enhanced dynamic q-range qmax/qmin in one instrument setting.
High magnetic fields, up to 17 T at the sample position, beam polarization and 3He spin analysis, facilitate and expand studies of magnetism and allow a more quantitative analysis of spin incoherent samples. The high flux allows for kinetic experiments with time resolution of the order of few milliseconds.
Applications
- Soft condensed Matter:
organic and inorganic colloidal particles; polymers blends or polymer in solution, gels, liquid crystals; self assembly of surfactant molecules. - Biology:
proteins, nucleic acids, biomembranes, vectors for drug delivery. - Material Science:
phase separation in alloys and glasses, morphologies of superalloys, microporosity in ceramics, interfaces and surfaces of catalysts. - Magnetism:
Flux line lattices in superconductors; magnetic correlations.
Layout shown in three parts
- Top:
neutron selection either with a neutron velocity selector (monochromatic mode) or with choppers (time of flight mode) - Middle:
collimation part - Bottom:
front and rear detector moving in the vacuum tube from 1.2 m to 12.8 m after the sample position.
3D instrument layout
Cold neutrons arrive from the left through guide H142. They successively cross the chopper housing and the collimators to reach the sample. The scattered neutrons enters the detector tank where they are collected by to sets of 3He tubes.
The casemate
Inside of the casemate, i.e. the housing where the beam is tailored to satisfy the needs of either the 'monochomatic' or the 'time-of-flight' mode of operation of D33.
The neutrons arrive from the right side and go the sample and the detector on the left side. In between, they successively cross a velocity selector (not visible on the photo) and four choppers. The boxes between the choppers are a polariser and a wavelength filter.
The sample area of D33
D33 was not yet commissioned when this photo was shot (July 2012) but neutron tests had already started. The sample table of D33 allows positioning in the vertical and horizontal direction and rotation in the horizontal plane as well as a goniometer for tilts in the vertical plane. The stages are dimensioned to carry weights up to 500 kg. The entire sample table and sample environments can be placed along the 2.8 m length between the collimation and the detector tank window.
The automatic sample changer
For soft-matter and biology studies the standard sample environment is often an automated sample changer with up to 22 positions for optical cells with a thickness of 1 to 5 mm (300-1500 µl). The temperature of the sample changer can be varied between 278 and 353 K with a double bath system that allows the user to switch rapidly from one temperature to another. The usual array of standard sample environments includes rheometer, shear cell, stopped-flow device, and acoustic levitator.
Inside D33
The dynamic q-range of D33 has been extended by using two large multitube detectors instead of one.
The photo shows Charles in front of the rear detector and 'framed' by the front detector.
A general view of the instrument
The long yellow tube is the SANS instrument D11.
D33 is the shorter tube just behind.