The general aspects of the undulator technology are described in close relation with both the accelerator technology and the spectral performance as light sources. In addition, we show the latest technology for future synchrotron radiation facilities such as cryogenic permanent magnet undulators or HTSC (high temperature superconductor) undulators.

Laser Compton gamma ray beam line on New SUBARU supplies quasi-monochromatic, polarized high energy photon beam. World highest class gamma-ray flux of more than 10⁶ photons/s is generated at photon energy range of 2 to 40 MeV.

Construction of STF (Superconducting RF Test Facility) is being carried out at KEK. The STF-Baseline superconducting cavity system, which includes four TESLA-like 9-cell cavities, input couplers and frequency tuners, has been developed for the future ILC project. A 6-m cryomodule including one of four TESLA-like cavities was assembled, and the cryomodule was installed in the tunnel for the initial test, called the STF Phase–0.5. The first cool-down of the cryomodule and high power tests of the cavity had been carried out at 2 K from October to November, 2007. The maximum accelerating gradient (Eacc, max) of 19.3 MV/m was achieved in a specific pulse width of 1.5 msec and a repetition rate of 5 Hz, (23.4 MV/m in a shorter pulse width of 0.6 msec). Compensation of Lorentz force detuning at 18 MV/m was successfully demonstrated by using a piezo tuner. The second cryomodule test for four cavities, called the STF Phase–1.0, is scheduled in July, 2008.

One of the biggest advantages of the digital low level rf (LLRF) system is its flexibility. Owing to the recent rapid progress in digital devices (such as ADCs and DACs) and telecommunication devices (mixers and IQ modulators), digital LLRF system becomes popular in these 10 years. The J–PARC linac LLRF system adopted cPCI crates and FPGA based digital feedback system. Since the LLRF control of the normal conducting cavities are more difficult than super conducting cavities due to its lower Q values, fast processing using the FPGA was the essential to the feedback control. After the successful operation of J–PARC linac LLRF system, we developed the STF (ILC test facility in KEK) LLRF system. Since the klystron drives eight cavities in STF phase 1, we modified the FPGA board. Basic configuration and the performances of these systems are summarized. The future R&D projects (ILC and ERL) is also described from the viewpoints of LLRF.

A quasi-monochromatic x-ray pulse has been generated via laser Compton scattering (LCS) with an electron bunch and a laser pulse. The LCS hard x-ray source consisted in a compact S-band 40 MeV linac and a Ti: Sa laser system has been developed at AIST and it has been applied to biological uses. The refraction contrast imaging of a biological specimen has been successfully demonstrated with the LCS hard x-ray. We describe the details of our LCS x-ray source, its applications to biological imaging study, together with a future upgrade plan.