A soft magnetic material for power supply systems of high energy physics experiments

Abstract

Most of the high energy physics experiments require their detectors to be embedded in a high intensity magnetic field. In particular the biggest of them, ATLAS, running in the CERN Large Hadron Collider (LHC) particle accelerator, generates a field of 2 T by means of a gigantic toroidal magnet working in open air. Its future phase 2 upgrade plans to move the DC/DC power supplies from the present positions on the external balconies directly on the detectors, where the field is of the order of 1 T. This presentation describes the development of samples made of special magnetic material for inductor cores suitable to work in such an environment. Starting from iron-silicon powders, at FN plant a plastic forming process, based on powder extrusion, injection moulding and sintering, was developed. To get the best compromise between the forming process requirements (good coupling among the metallic powder and the organic components to assure the right mouldability) and the debinding and sintering conditions, several mixtures (with different percentages and kind of organic additives) were experimented. A proper mould was designed and realized to get torous-shaped prototypes. The preliminary results of the physical-microstructural characterization performed on the first prototypes made will be shown.