Undulator Mobile Carriages
Standard Support Structures
To simplify the manufacture and reduce the cost, the mobile carriages are standardized. A precise mechanical interface is used between the long rigid girders of the carriage and the magnetic assemblies. Consequently, any magnetic assembly is designed to fit on any carriage. The carriages are produced by series of 5-10 units industrially. After delivery to the ESRF, they are equipped with magnet assemblies in the ID Lab. 5 m long undulators are made of three segments each installed on its own carriage. Special magnetic assemblies are placed at the ends of each segment which leave a gap of a few millimetres between the adjacent segments and maintain almost perfect phasing on all useful harmonics of the spectrum.
A few special carriages have been produced to accommodate the variable polarization undulators which allow an indpendent setting of the vertical and horizontal magnetic field as well as the phase between them.
Main Characteristics
- Physical length 1.6 m
- Maximum magnetic force: 10 tonnes
- Maximum gap speed 10 mm/s max
- Gap resolution: 2.5 micrometers
- Gap and taper motion by two high speed stepper motors
- Gap and taper monitoring by two absolute multiturn encoders
- Magnetic force compensation by Belleville springs
