On July 1, the last shielded bellows was connected in the tunnel, completing the installation of the High Energy Photon Source (HEPS) storage ring and signifying that all components of the HEPS storage ring have been linked up and the storage ring is ready for inter-system commissioning.

The perimeter of the HEPS storage ring is about 1360.4 meters and is mainly used to store high-energy and high-quality electron beams in order to emit high performance synchrotron radiation X-rays. It is the third largest light source accelerator in the world and the largest accelerator in China. It consists of 48 modified 7-bend achromat lattice units that achieve a horizontal natural beam emittance of better than 60 pm·rad at an energy of 6 GeV.

After completion of the main equipment installation on Dec. 11, 2023, installation and commissioning work on the vacuum, injection and extraction, RF, cryogenic, insertion device, power supply, beam instrumentation, control and other systems of the HEPS storage ring began immediately. During a period of less than seven months, HEPS team members worked overtime and exhibited excellent coordination ability and team spirit so as to fulfill a seemingly impossible task. With completion of the storage ring installation, inter-system joint commissioning immediately began. After it is completed, beam commissioning will begin.

Over the past five years, the linac and booster have both passed scientific and technical performance acceptance reviews organized by the HEPS Project Management Department, with the electron beam energy accelerated to 500 MeV and 6 GeV separately. All parameters reached or exceeded design specifications, with the overall performance of the linac and booster reaching the global advanced level. Once completed, HEPS will not only be the first high-energy light source in China but also one of the brightest fourth-generation synchrotron radiation facilities in the world.

Fig.1.Vacuum connection of the last period in the storage ring tunnel (Image by IHEP)

Fig.2 & fig.3. Installation work in the storage ring tunnel (Image by IHEP)

Fig.4. HEPS team members (Image by IHEP)