Doors wide open for PANDA: Yoke of solenoid magnet assembled


The developments for PANDA, one of the key experiments of the future accelerator center FAIR, are progressing steadily. Another important stage has now been reached: The yoke of the PANDA solenoid magnet was fully assembled at the steel construction company SET in Novosibirsk. The final tests of doors were done recently.

The assembly of the yoke octants is aided by a star shaped installation tool. After its removal, the octants stayed in place with minimal deviation. All parts are surveyed with a laser tracker employing fixed fiducial marks even during the assembly process, which facilitates the whole operation providing much better precision. No mechanical stoppers are used, as their precision would be too low.

The four doors, two downstream and two upstream, are bolted to the yoke in their closed position. Before opening the doors, the bolts are unfastened and the doors are lowered to the sliding rails resting then on heavy weight rollers. The 22 tons door wings were opened sliding on the rollers with a friction of only about 0.5%: Two persons were able to move one wing with a simple manual winch.

In the final configuration, the Budker Institute for Nuclear Physics (BINP) will equip the doors with hydraulic jacks and actuators, which were not part of the deliverables of SET. The yoke was again disassembled and the parts will be transported to BINP. There, they will be assembled into the complete magnet.

Currently the cryostat of the superconducting solenoid is in production. At the same time, the production of the superconducting wire is in preparation. The assembly of the entire magnet at BINP will take place next year and allow first tests. It is finally planned, to perform a precision field mapping of the large active volume of the magnet, where in future particle tracks will bend to be detected by the PANDA experiment. (BP)