Design and status of construction of Finuda superconducting aluminium stabilised detector

The Finunda magnet, one of the two detectors for DAΦNE, the Frascati Φ factory, is currently under construction at the Ansaldo workshops. Under general specifications granted by INFN, Ansaldo designed the complete magnetic system including cryostat, the shaped iron yoke, the data acquisition, the safety and controls, the translation trolleys for the magnet displacement out of the beam axis. The Ansaldo order will be completed with the acceptance tests at the Ansaldo premises and installation in the experimental site in Frascati. This paper describes the magnetic and mechanical design of the about 3 m diameter solenoid and its cooling method (thermosiphon), the 240 ton iron yoke, the displacement system. The state of the art of the construction processes is also reported with a special emphasis on the winding of the superconducting cable inside the aluminium support structure