SPECS 2D-CCD, Руководство пользователя

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Manual V2.docx | Status 10.12.2015 | Version 1
The purpose of the coil lens is to rotate the spin polarization vector, but inevitably the coil
also has a focusing effect. Since the focusing is proportional to the square of the coil current,
it is possible to rotate the spin polarization vector (and the image) while keeping the focusing
power constant by changing the direction of the coil current.
There is thus an advantage in switching between the spin angle between –45 and +45
degrees instead of switching from 0 to +90 or –90 degrees: We keep the focal length of the
solenoid constant for both spin rotation directions, thus the electron optical trajectories are
equivalent for both +45° and −45° degrees spin rotation.
90° deflector 5.2
The spin polarization vector, S, does not change in an electrostatic field. An electrostatic 90°
deflector can thus convert a longitudinal spin component into a transversal one, as shown in
Figure 14 (figure after J. Kessler: Polarized Electrons, Springer).
Figure 14. Principles of the 90° deflector
The 90° deflector can also be used as steering element into the spin detector. This is
achieved by adjusting the voltage between the 90° deflection elements by setting
SpinDeflection2X. SpinDeflection2Y applies a deflection voltage between the top and bottom
plate of the 90° deflector, and thus deflects the beam in the direction normal to
the 90°
deflection plane. See "Optimizing the Signal" in section A.3 for a detailed description of
how to adjust these parameters.