No abstract

The ESS-Bilbao facility, hosted by the University of the Basque Country (UPV/EHU), envisages the operation of a high-current proton accelerator delivering beams with energies up to 50 MeV. The timeaveraged proton current will be 2.25 mA, delivered by 1.5 ms proton pulses with a repetition rate of 20 Hz. This beam will feed a neutron source based upon the Be (p,n) reaction, which will enable the provision of relevant neutron experimentation capabilities. The neutron source baseline concept consists in a rotating beryllium target cooled by water. The target structure will comprise a rotatable disk made of 6061-T6 aluminium alloy holding 20 beryllium plates. Heat dissipation from the target relies upon a distribution of coolant-flow channels. The practical implementation of such a concept is here described with emphasis put on the beryllium plates thermo-mechanical optimization, the chosen coolant distribution system as well as the mechanical behavior of the assembly.

No abstract

Efficient cooling of the target material is a key issue in the design of a spallation target. The aim of the RTFT (Rotating Target Flow Test) facility at ESS Bilbao (Zamudio, Spain) is the characterization of coolant flow in rotating targets. Maps of flow velocity along cooling channels are obtained with PIV (Particle Image Velocimetry) techniques. Tests are performed with water flowing at up to 30 l/s and 5 bar, for different disk rotation rates, and are used to evaluate target designs in terms of potential flow instabilities and adverse effects -such as flow stagnation and recirculation-, to benchmark calculation and simulation models, and to assess final target designs.ESS Bilbao and SNS have recently performed a first test campaign on a full scale mockup of the latest SNS design for a 1.5MW rotating target. Tests included runs at several operation conditions, plus an emergency stop simulation, for observation of the water flow evolution in a pump sudden stop event.