SPring-8 Upgrade Project: Accelerator Redesigned and Restarted.

For decades, synchrotron radiation facilities have provided powerful research tools for a variety of photon sciences, industrial use, and other purposes. In [[9]], we discussed the suppression of emittance variation in extremely low emittance light sources and demonstrated that the emittance variation could be reduced to less than 1% and passively maintained by carefully optimizing the operating condition of insertion devices. The electron energy was optimized at 6 GeV to reduce the natural electron emittance, while covering the same range of X-rays with shorter period undulators. There is no such magnet for NanoTerasu and, more importantly, the LGB magnets are expected to be made using a permanent magnet for SPring-8-II that does not exist for NanoTerasu. [Extracted from the article]