Neutronic and thermo-mechanic calculations for the design of the TRADE spallation target

The spallation target of the TRADE Project-at present in stand-by waiting for further decisions on budget availability-is based on the concept of a solid target cooled by forced convection. The solid target approach presents a maximum power density limitation due to the high thermal stresses which are generated by the huge differential temperatures in the material. These at their turn stem from the proton energy loss in the volume of the target material and the water cooling on the external surface. The maximum operating beam power and the proton beam profile were imposed by experimental and geometrical considerations; the peak power density of the target material (Tantalum) turned out to be about 8E09 W/m3. The power generation of the reference configuration of the spallation target was accurately calculated by the code MCNPX, which allows to simulate individual particle tracks in 3-D geometry, starting from the accelerated 140 MeV protons down to all the relevant secondary particles. The temperature distribution and the stress and strain maps were calculated by the thermo-mechanical ANSYS code. The main calculation results are reported. The elastic-plastic analysis of the target material is performed in terms of maximum allowable deformation, fatigue and progressive plastic deformation.