Synchrotron radiation facilities are indispensable in numerous forefront areas. Until now, the electron energies of all photon sources in China have been in the medium- and low-energy regions. However, research related to national security and industrial innovation has demonstrated the urgent need for high-performance sources with high electron energy. For this purpose, a complex for advanced photon sciences in northern China has been planned since 2009. The complex is planned in three phases. In the first phase, a storage-ring-based, high-energy photon source (HEPS) with a beam energy of 5 GeV and emittance less than 1.0 nm？rad will be constructed, which can provide high-brilliance hard X-rays to several tens of experimental stations. In the second phase, a superconducting linac will be constructed to drive an X-ray free electron laser (XFEL), serving as an extension and compliment to the HEPS. In the third phase, as one possible performance upgrade scheme, the ring and the superconducting linac will be connected to form an energy recovery linac (ERL) system. The schematic drawing of the proposed photon science complex, including the three phases, is shown in Figure 1.

Fulltext: https://www.tandfonline.com/doi/full/10.1080/08940886.2014.970938