Motion and Positioning Equipment for 10-8 hPa
The instrumentation inside the vacuum tank included requirements for four degrees-of-freedom lens alignment and long-stroke positioning of an aperture in the focus. Essential for the application is a long-term position stability combined with a very high positioning resolution. All motion axes had to be decoupled from the chamber. For motion control, a common electronics and software platform was chosen, so all axes are controlled over the same user interface which can be integrated in the hutch’s TANGO software environment. For lens alignment, a parallel-kinematic 6-DOF SpaceFAB robotics was chosen, that allows flexible setting of the pivot point by software. The very stiff design is low-profile and provides the required travel ranges of 50 mm (X), 3 mm (Y) and 20 mm (Z) with a linear resolution of 1 μm. Tilting adjustment in all angles can bedone over ±2.5 degrees with a resolution of 0.0003°. The aperture can be positioned over 500 mm stroke with 10 μm resolution using a customized UHV stage. All axes use UHV-compatible stepper motors.