In the past few months, the first D2 corrector prototype, built by a Chinese collaboration steered by IHEP in Beijing, has been completed. The magnet was manufactured by Western Superconducting Technologies, Xi'an and was tested at 4.2 K in the Institute of Modern Physics, Lanzhou. The magnet reached the ultimate field in both apertures, as required by specifications.
We observed a long virgin training in both apertures; even though the project sets no requirement on the “virgin” training, the total of 100 quenches took much time and effort to IMP colleagues. The retraining was much faster, with one quench to nominal and ten to ultimate, but still not reaching our specification (one quench to ultimate). The behavior is close to what was observed in the Aperture 2 of the first prototype MCBRDP1 manufactured at CERN, which also required long training and very fast retraining. Investigations are ongoing to improve these aspects.
The magnet confirmed all the other features of the design developed at CERN and achieved the important milestone of completing the technology transfer to the Chinese collaboration. The magnet is now on its way to CERN where it will be tested at 1.9 K. The activities for manufacturing the first series magnet started last month in Bama, Suzhou.