ESS target helium experiments at Lund University

In ESS, a 5 MW proton beam will hit a helium cooled tungsten target to generate neutrons by spallation. For the purpose of investigating various aspects of cooling with helium, an experimental system has been constructed at Lund University, Department of Energy Sciences. A helium flow of 3 g/s is circulated in a closed loop with pre-heater, cooler, filters and a test vessel. The vessel has windows for measurements and is designed for 10 bar and above 400°C. In the test vessel, a tube forms a helium jet of up to 150 m/s onto a coin shaped material sample. One purpose of the system is to investigate erosion of sample surfaces. Drilling and attaching equipment to the surface had to be avoided, so the setup has been benchmarked and the comparison was used to tune a CFD model. Then the model is used to assess the conditions in the experiments. The setup, as well as the tests and calculations, are described and it is concluded that the temperature and velocity estimates are sufficient for the experiments to be performed. (Less)