Aligna
®
4D User Manual
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Open detector covers, align the two spots for hitting the detectors. If detectors are hit
(intensity is seen) use scope dots at PC screen (green=beam position, red=beam an-
gle) for finer alignment of the beam sampler or the mirrors inside the detector setup.
Set detector sensitivity
o Click button "AutoGain" to force an automatic detector gain setting, fitting to the actual
test beam intensity. The PSD gain values are displayed in "%": 100% indicates typical
test beam intensity. The values, found in "auto gain" procedure should be in the range
of 10%...300%.
If intensity is too high (gain < 15%) use neutral density filters in the test beam path!
If intensity is too weak (gain > 1000 %) use other beam sampler or other mirror coat-
ings (please refer to chapter on Beam Sampler Requirements)
o When both intensity signals are in the recommended range of 1..5 Volts the main beam
or just the test beam can be aligned for better hitting the mid of the detectors, observ-
ing the displayed 4D pointing
Switching on the Regulator ("RegOn" Button)
o If intensity is displayed at “A” AND “B” (red and green bar at the intensity devices "A"
and "B"), LEDs “Intensity A” and “Intensity B” are lit, “IntensityOK” near “RegOn” button
at screen), regulator can be switched on
o If the setup in use is similar to that, which was used when setting the default parame-
ters (at TEM Messtechnik GmbH before delivery) the system should stabilize now an-
gle X/Y and position X/Y going to 0,0,0,0 positions at the X/Y scope screen.
In case the optical setup has changed (strong variations of the distances between the actua-
tors and/or distance from second actuator to the detector, additional mirrors in the beam path,
changing the direction of fold mirrors (exchange of X and Y, e.g.), a correction of signs and
gains of the four servo loops may be necessary. This will be described in following chapters.
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