Photon Factory has been operating since 1982, thus is a typical second generation facility. However, the emittance of the ring has been decreased from the initial 300nmrad to 36 nmrad through twice major improvements of the lattice. Thus the Photon Factory is approaching to the so called the third generation source in the view point of the emittance.

In general the number of straight sections is limited in the second generation sources. Photon Factory's 2.5 GeV storage has 7 insertion devices including one superconducting vertical wiggler. Upgrade of straight sections aims to elongate the length of the existing straight sections (BL-2, 5, 13, 14, 16, 19, 28) and create 6 new straight sections (BL-1, 3, 15, 17, 4, 18). Among these, 4 in-vacuum short gap undulators can be installed and provide X-rays. Beamlines 2, 13, 16, 19 and 28 will be dedicated for VUV/SX experiments by replacing the insertion devices and beamlines.

At the first stage, the Photon Factory 2.5 GeV storage ring cannot provide the beam between March and August, 2005 in order to replace the accelerator components and install a new undulator. We analogize for your inconvenience and thank for your cooperation.

The improvement of the beamlines is progressing. The old BL-28 has been removed and new optics designed for high energy resolution ARPES/PES has been installed during the summer shutdown of 2004. High performance, high energy resolution, high flux, are already confirmed. The design of the new structural biology beamline BL-17 using in-vacuum short gap undulator is progressing and will be installed during the shutdown of 2005. The calculated spectra are shown below.

Through these improvements, the Photon Factory can provide synchrotron radiation very close to that of the third generation sources.