Superconducting Detector Magnet for BabyIAXO

BabyIAXO, a 20 m-long telescope aiming at the search for solar axions, is planned since late 2017 as a smaller scale but fully functional demonstrator of the International Axion Observatory (IAXO). It essentially comprises a superconducting magnet, optics and X-ray detectors, installed on a Sun-tracking drive system providing rotation and tilting of the detector. The preliminary design of the BabyIAXO magnet has been developed with time and the most recent modifications are reported. The magnet concept is based on using Al-stabilized NbTi conductor in a common-coil winding layout, fully resembling the baseline IAXO design and providing two free bores of 700 mm diameter and 10 m length with a magnetic field of about 2 T. The key challenges for construction and operation of the conduction cooled 40 MJ BabyIAXO magnet are addressed, such as procurement of the conductor, quench protection of the magnet components and magnetic shielding of vacuum and cryogenic equipment. Following the lab-scale experiments carried out to verify the magnet concept, their relevance and main results are further discussed before taking up the construction of the full project anticipated in 2020.