The Laboratory for Laser Energetics (LLE) is a scientific research center that is part of the University of Rochester in the USA.
The LLE specializes in the study of high-energy physics, specifically when the interaction of extremely intense laser radiation with matter is involved.
The OMEGA laser at the LLE is one of the most powerful and highest-energy lasers in the world. It can deliver 40 kJ onto a target less than 1 millimeter in diameter thanks to its 60 beams.
The LLE wants a hexapod to position the OMEGA laser target with a high angular resolution of 1 µrad.
The hexapod environment is full of radiations: neutrons, X-rays, gamma rays. The ElectroMagnetic Compatibility (EMC) constraints are high.
The system has to carry a through-all load of 230 kg while resisting vacuum efforts of 3400N. There are forbidden volumes all around the payload and the hexapod, in order to enable inspection cameras to enter.
Symetrie offered a hexaglide parallel-kinematics system, in order to be compatible with the maximum allowed diameter and a large through-all payload.
With a hexaglide, struts have a fixed length and are actuated by rails. Like a hexapod, this architecture also brings six degrees of freedom: three translations, three rotations.
Special attention has been taken to the stiffness of the system. Finite element analysis and tests on the hexaglide have been done with our partner V2i. We were sure to obtain nice results on the demanding specifications before starting manufacturing.
■ Resolution: 1 µrad with a pivot point 2.5m away from the mobile platform
■ Stability of 0.2 µm over 60 min
■ High stiffness
■ ISO5 cleanliness
■ Large dimensions: 780 mm diameter, 830 mm height
■ Heavy load: 230 kg + 3400 N efforts due to vacuum