Electron accelerator S-DALINAC
Electron accelerators are large physical facilities, which accelerate charged particles close to the speed of light. Such instruments are primarily used in fundamental research. Due to the hight accuracy requirements, usually laser trackers are used to align the elements of the beam guidance. The distance measurement unit of the laser tracker is the crucial component of the instrument. The specified uncertainties of a measured position is ≪0.1 mm. In contrast to classical geodetic instruments like a theodolite or a total station, the observations of a laser tracker are usually not related to the plumb line because the instrument is not levelled. For that reason, common geodetic adjustment tools fail to process laser tracker measurements.
The open-source adjustment package JAG3D allows for a rigorous network adjustment of laser tracker measurements based on the original observations. The unnecessary conversion to Cartesian coordinate triples is omitted. For that reason, the interpretation of the adjustment results are more intuitive because the well-known reliability quantities can be directly assigned to the original measured values and do not swamp into functions of measured quantities. Moreover, measurements obtained by total stations or additional levelling loops can be rigorously combined with laser tracker data on the observation level. The software was successfully validated using data sets from the Deutsche Elektronen-Synchrotron (DESY, German Electron Synchrotron) as well as real data from the FRIB superconducting linear particle accelerator (LINAC) at Michigan State University.
