Design and development of a reduced form-factor high accuracy three-axis teslameter

Acknowledgments: The authors would like to thank Reuben Debono for his useful guidance and help in the PCB assembly of the instruments at the Electronic Systems Lab at the Faculty of Engineering at University of Malta. The authors would like to thank R. Ganter, project leader of the Athos undulator beamline and H-H. Braun, SwissFEL machine director, for their constant support throughout the entire project. The authors would like to thank Sasa Spasic and his team at Sentronis facilities for their fruitful discussions and their guidance during testing.A novel three-axis teslameter and other similar machines have been designed and developed for SwissFEL at the Paul Scherrer Institute (PSI). The developed instrument will be used for high fidelity characterisation and optimisation of the undulators for the ATHOS soft X-ray beamline. The teslameter incorporates analogue signal conditioning for the three-axes interface to a SENIS Hall probe, an interface to a Heidenhain linear absolute encoder and an on-board high-resolution 24-bit analogue-to-digital conversion. This is in contrast to the old instrumentation setup used, which only comprises the analogue circuitry with digitization being done externally to the instrument. The new instrument fits in a volumetric space of 150 mm × 50 mm × 45 mm, being very compact in size and also compatible with the in-vacuum undulators. This paper describes the design and the development of the different components of the teslameter. Performance results are presented that demonstrate offset fluctuation and drift (0.1–10 Hz) with a standard deviation of 0.78 µT and a broadband noise (10–500 Hz) of 2.05 µT with an acquisition frequency of 2 kHz.peer-reviewe