The Science Directorate at the European Spallation Source (ESS) invites applications for an instrument scientist for the dedicated Test beamline (TBL).

The Diffraction and Imaging Division is home to the instrument scientists and instrument operational engineers responsible for designing, constructing, and operating the DREAM, MAGiC, BEER, HEIMDAL, ODIN, and TBL instruments at ESS. New designs for a wide range of neutron instruments are being implemented to fully leverage the unique long-pulse time structure of the ESS neutron source.

The primary purpose of TBL is characterizing the target-reflector-moderator system and verifying the performance of the neutron source based on operating parameters such as proton beam energy, stability, pulse length, and beam rastering, as well as the moderator conditions. An important aspect of this work will be comparing the measured and simulated neutronic performance of the moderator, providing a crucial reference for various neutron scattering instruments. Additionally, the TBL will contribute to optimizing instruments and methods to fully exploit the unique long-pulse time structure of the ESS neutron source. The TBL will function as a local characterization station, supporting technical developments in areas such as neutron optics, polarization, and novel detectors. It is designed to support the user program by performing exploratory imaging experiments, neutron diffraction studies, and single-crystal alignment. Due to the flexibility of the instrument, a variety of detectors and sample environments can be fitted inside the experimental cave, allowing multipurpose measurements on not only thermal neutrons but also epithermal/fast neutrons and gamma rays. This includes but is not limited to a well-established technique such as time-of-flight transmission measurements, neutron tomography, neutron activation analysis, grating interferometry, etc. As the facility evolves, the modular design of the TBL will allow for modifications to meet new objectives, ensuring its continued relevance and utility in advancing neutron science. The construction of TBL is completed and the team prepares the instrument for the first neutrons.