A 500-kV, 10-mA photocathode DC gun which is designed for next-generation light-sources based on energy-recovery linac has been developed in a collaboration effort of JAEA, KEK, Hiroshima Univ. and Nagoya Univ. We have utilized a segmented cylindrical ceramic insulator and guard-ring electrodes to prevent any damage to the insulator from electrons emitted by the support-rod electrode. The 500-kV gun was successfully conditioned up to a voltage of 550 kV and a long-time holding test for 8 h was demonstrated at an acceleration voltage of 500 kV. The 500-kV gun consists of a Cockcroft-Walton generator, a segmented cylindrical ceramic insulator, guard-ring electrodes, a support-rod electrode, a vacuum chamber, and a pressurized insulating gas tank. The cathode electrode, anode electrode, and beam line apparatuses are now under fabrication and beam tests of the gun will be started soon.

High gradient effort on 1.3 GHz superconducting cavity of single cell and 9-cell was started around 20 years ago. Many efforts and developments have been made and the TESLA technology became a baseline of cavity fabrication and surface treatment of XFEL cavity and ILC cavity. However, ILC goal which is 35 MV/m@Q0=8E9 with 90% yield is a little beyond of the present status. Continuous effort for high gradient with high yield has been made to reach ILC specification. The opportunity of the construction of surface treatment facility at KEK-STF advances the research of the cavity high gradient. The optimization of the electro-chemical facility by the chemical analysis, surface analysis and the coupon experiments has been done. The optical observation of the cavity inner surface together with quench localization technique suggests that some defect is responsible for quench at low gradient. The electromagnetic calculation and defect removal tool suggests the understanding of defect and its solution. This paper covers the topics that are now under research and in progress at KEK-STF.

International Fusion Materials Irradiation Facility (IFMIF) is an accelerator-based neutron irradiation facility dedicated for development of fusion materials. Engineering Validation and Engineering Design Activities (EVEDA) phase of IFMIF project has been initiated in June 2007 and a prototype of the IFMIF accelerator Deuteron is under construction in Rokkasho, Aomori. The target of the prototype is 9 MeV-125 mA CW beam operation, which is full scale prototyping up to the first tank of superconducting linac section. In this report, the major technical specifications and issues of this extremely high-power machine are overviewed and expected results through operation in future are summarized.

Brief introduction is given of the new accelerator installed this March at the Quantum Science and Engineering Center (QSEC) of Kyoto University. The tandem type accelerator (6SDH-2, NEC, USA) has the maximum terminal voltage of 2 MV and is capable of delivering energies of 2(q+1) [MeV] for ions with charge state q. Chief specification of the machine and the aim of research & education are described. Historical role of the accelerator laboratory of QSEC and the budget strategy network of universities are also introduced.

International Linear Collider Workshop 2010 (LCWS10 and ILC10) was held in the Friendship Hotel at Beijing from 26^th March to 30^th March 2010. This workshop is a joint effort of Accelerator and Physics/Detector groups for the International Linear Collider (ILC). I joined this workshop as a researcher of Superconducting RF linac. In this article, I would report the presentations/discussions/activities of the workshop.

The 14^th Beam Instrumentation Workshop (BIW10) has been held in Santa Fe, NM on May 2–6, 2010 sponsored by LANL. This biennial workshop was dedicated to exploring the physics and engineering challenges of beam diagnostics and measurement techniques for charged particle accelerators. The outline of the workshop, including personal impression is shown.

Nowadays, study abroad is a kind of popular things. Sending young researchers abroad for one or two years seems to me a trend or fashion in Japan. However, living overseas as a physicist for more than a decade is still not so common lifestyle. I was one of such unusual guys, and returned to Japan in autumn in 2008. By using this opportunity, I will scribble my clumsy experience overseas.