Photon Factory activity report, 1989

At the Photon Factory about 500 experiments are now running annually with about 50 experimental stations, the total operation time of the 2.5 GeV storage ring was 3400 hour in 1989, and the number of users was more than 2000, including 300 scientists from industry. This wide usage of synchrotron radiation has been supported by good performance of the accelerators. The positron beam current of the linac was increased for rapid injection (injection time: 20 min). The entire roof of the Light Source building was covered with thermal insulator (urethane-foam). This has greatly improved the beam stability of the ring. It has been operated at an initial ring current of 350 mA with a life time of 20 hours. Distinctive instrumentation at the Photon Factory has expanded to various fields such as angle-resolved ion-spectroscopy, dispersive EXAFS, trace impurity X-ray fluorescence analysis, plane-wave topography, structure analysis under high pressure, and imaging plates. Recently, experiments of protein structure analysis have been carried out extensively; Sakabe developed a new type of Weissenberg camera for protein crystallography, and about 50 experiments have been done for the past six months by a combination of Sakabe camera and imaging plates. The 2.5 GeV light source is now at an entrance of its harvest season. The TRISTAN Accumulation Ring has been used throughout this year in a time sharing basis with the TRISTAN experiment; twenty minutes for injection to TRISTAN Main Ring and 2 hours for SR experiment. The main subject has been magnetic Compton scattering with circularly polarized wiggler radiation. Such experiences enable us to expand our perspective for research in the following decade; we are investigating the possibility of operating the TRISTAN Main Ring at 6-8 GeV with 6000-pole undulaters, resulting in an extremely brilliant radiation source (Emittance: 0.1 nm·rad at 5 GeV with damping rings). (J.P.N.)