The superconducting wiggler of the High Energy Photon Source Test Facility (HEPS-TF) passed its cryogenic vertical test on April 15^th. The test group, composed of experts from Shanghai Synchrotron Radiation Facility (SSRF), China Institute of Atomic Energy (CIAE), the University of Science and Technology of China (USTC), and the Institute of High Energy Physics (IHEP), participated in the field test at IHEP.

At the test site, the test group heard presentations on the research background and the design and development of the magnet, reviewed the test procedure, and carried out the field test. The test results showed that the critical current of the superconducting wiggler 3W1 magnet reached 350 A after 17 quench trainings. The magnetic field was measured with a Hall probe sensor under 345 A current. The magnetic field distribution was consistent with simulation results. The maximum peak field was 2.61 T, which met the design requirements.

The superconducting 3W1 magnet is the first superconducting wiggler developed in China, and is also one of the research goals of the HEPS-TF insertion device system. This magnet has very large air gap, high magnetic field and very large stored energy. After numerous experiments, the project team solved many problems and came to a full understanding of the key technology for the fabrication and assembly of the superconducting wiggler.