Introduction: The Authomatic Beamline Alignment

Synchrotron or Free Electron Laser Facilities can be used for chemical, physical and biological experiments. Due to the characteristics of the experiments the light has to be collimated, monocromatised and focused on the sample under test; this is done by a "beamline" made of several sets of highly sophisticated and expensive optic parts.

The success or performance of experiments is strongly affected by the alignment conditions i.e. all the optical components must be set to optimize some parameters such as flux or resolving power at the experimental station.

The manual alignment procedures currently used have some drawbacks: they are time consuming, the require well trained staff, they are boring for the optics experts and sometimes error prone, which could result in a sub-optimal use of the light beam and hence in a sub-optimal quality of the experimental data.

An automatic alignment system could contribute significantly to the reduction of these drawbacks and lead to an effective exploitation of extraordinary features of the new generation light sources.

Now, the development of such a system is really difficult. The propagation process of the light beam through the beamline has a complex structure, which can be different from experiment to experiment. Even the alignment purpose itself can differ from beamline to beamline: the main goal could be optimisation of flux, resolving power or any combination of these or other parameters. Many beamlines have not been designed with the automatic alignment problem in mind: we have to cope with intrinsic limitations of sensors and actuators. Moreover, if the beamline is already operational, the time available to test an automatic alignment system is generally very limited.

The Automatic Beamline Alignment information center has the primary goal of keeping the interested people in touch, acting as a virtual forum of discussion. Moreover, we want to set up a repository of all the available know how, the available tools, the available documents and links relevant to the subject.