This slit system was originally designed for a neutron reflectometer where the accuracy and resolution as well as the parallelism of the slit blades are extremely important. In fact, the accuracy of the collimation provided by the slits can be directly correlated to the resolution of the experiment.

As for the other IB slits, each blade can be moved independently over the full aperture and are all fully overlapping.

The slit blade pair will remain parallel to each other and to the reference frame over the entire range of motion within 50 µrad (10’’), and the accuracy, resolution and repeatability is < 1 µm over full range.

The slit blades for neutron reflectometers will typically be made of rectangular cut B4C blocks with a surface roughness Ra  ̴ 0.5 µm and a straightness < 2 µm over the full length.

The aperture size can be chosen to match the specific instrument.

Key facts:      
Aperture size Maximum: typically 60 mm x 40 mm
Minimum: Full overlap
Resolution 0.2 µm
Accuracy ± 1 µm over full range
Repeatability 0.5 µm
Blade parallelism 50 µrad over full range
Common options             Blade material and thickness: B4C in 3 mm, 5 mm, 7 mm
Motors: Custom high resolution stepping motors, including IMS motors
Encoders: Back-axle rotary encoders and/or internal Renishaw linear encoders