General Information:
The system 3002.60M was developed for positioning a cross slit screen as close as possible to the sample. Thus it is possible to precisely define the beam entry to the sample and/or the beam exit
to the detector. Attention was paid to achieving compact dimensions.
The interior is vacuum suitable. Thus, the system is ideal for low-energy beam applications.
Technical Details:
Step motors mounted on the outside of the housing drive the mechanism via vacuum manipulators. The maximum aperture size is 4mm x 4mm. The aperture is equipped with limit switches to prevent
collision and damage when opening or closing. The front of the system consists of an easily replacable kapton window and on the back is a KF flange for simple adaption to other optical components
such as Huber vacuum slits, Huber vacuum polarisation analysers or Oxford-Danfysik detectors. Mounted on the side is a vacuum connection for evacuation of the cross slit system.
Appliction fields:
Usual applications are diffraction experiments with grazing incidence applied to small samples. Without a slit system the beam would generate overspill near the sample which would lead to a large
increase of background scattering (see image).
Typical incremental angles of <0.3 degrees and sample sizes of approx. 10 x 10mm require the incoming beam to be limited to approx. 50µm both vertically and horizontally in order to prevent an outshining of the sample.
The ideal method for defining the incoming beam is to position an aperture as close as possible to the sample. This both reduces imaging errors and the divergence of the beam, and also ensures that the ideal segment of the sample is exposed to the beam.
In the same way, an exit beam aperture in the immediate vicinity of the sample ensures that only radiation diffracted from the sample is detected. This in turn additionally reduces background scattering.
1. Beam entry without tube slit screen
2. Beam entry with tube slit screen
3. Beam exit without tube slit screen
4. Beam exit with tube slit screen
