Danish quality control of critical metals for CERN

The metallurgists at the Danish Technological Institute in Aarhus have measured critical metallic phases in the iron cores of CERN's superconducting magnets.

The particle physics facility CERN in Switzerland is built around a series of accelerators containing powerful superconducting magnets, each with a length og15 meters. The inner core of the magnets is made of non-magnetic steel to prevent the steel from affecting the magnetic field. The requirement for the precision of the magnetic field means that only very special steel alloys may be used, and the risk of material defects is a major concern for CERN.

The Danish Technological Institute has been responsible for the quality control of the raw materials for CERN's latest magnets, which, among other things, are subject to large temperature changes when in use.

- When the magnets are cooled and heated, there is a risk that magnetic phases will develop in the iron. We have received a series of items from different production batches for CERN, which we have tested and used e.g. various etching agents on to make specific metallic phases stand out clearly, says Phillip Hjelmeborn Kaae, consultant at the Danish Technological Institute.

The task has been an exciting technical challenge for the Danish Technological Institute, where the collaboration with CERN also meant changes to the standards that the facility normally uses for metallic analyses.

- Working with CERN is both challenging and enriching. We carry out quality control via metallic analyses for several Danish companies, and this task has helped us become better at these types of tasks, says Phillip Hjelmeborn Kaae.

The Danish Technological Institute's materials division has more than 120 specialists, including the metallurgic experts.