The superconducting RF test facility (STF) in KEK is aiming to promote R&D of superconducting linear accelerator to be used in the International Linear Collider (ILC) and other advanced accelerator concept. The STF construction is planned to be sub-divided into two parts. They are phase–1 plan and phase–2 plan. The phase–1 plan is aiming to have quick experience on all aspects of 1.3 GHz SC cavity and cryomodule technologies by producing 4 TESLA- shape cavities with 5 m cryostat and 4 LL-shape cavities with another 5 m cryostat, which are powered by 5MW klystron. The other aspect of phase–1 development is to construct new cavity surface treatment facilities, such as electrochemical polishing and clean room to achieve cavity high performance. The developments of the phase–1 were completed in the end of 2008. STF is now entered to the new phase, STF phase–2. On a way of phase–2 construction, the intermediate programs such as ’S1-Global’ and ’Quantum beam accelerator’ will be conducted. The overall concept, plan and schedule are introduced.

This paper describes a long-pulse 1.3 GHz klystron modulator that was recently developed for the Superconducting RF Test Facility (STF) at High Energy Accelerator Research Organization (KEK). The modulator has a directswitched-type design with a 1:15 step-up transformer and a bouncer circuit to compensate the output pulse droop within 土0.5%; it can drive a klystron up to 10 MW peak power, 1.5 ms rf pulse width, and 5 pps repetition rate. The main features of this modulator are four 50 kW switching power supplies in parallel to charge storage capacitors to 10kV, self-healing-type storage capacitors to realize a compact capacitor bank, and a highly reliable IGBT switch which enables elimination of a crowbar circuit. Design considerations and its performance are presented. An IEGT (Injection Enhanced Gate Transistor) switch, composed of six series devices with a rating of 4.5 kV and 2100 A–DC, has been also developed and tested for R&D to realize a compact modulator.

It was shown in Mini-Workshop on Laser-Assisted H^－ stripping held at SNS on Feb. 18–19, 2009 that the laser stripping development has come into a new phase. The main subject of this phase is how to supply laser pulse with necessary energy density to every H⁰ micro-bunch which comes at a repetition rate of hundreds MHz. An exposition is also given on the reason why the laser stripping development has been undertaken, the Doppler broadening of the laser frequency as the most serious problem, two methods proposed to overcome this problem, and development of Proof-Of-Principle experiments of these methods.

Energy-recovery linac (ERL), which produces a small-emittance beam with high-average current, is a promising device for future light sources. In Japan, we have organized a collaboration team toward future ERL light sources and started R&D efforts to establish accelerator technologies for the ERL light sources. In this paper, we describe status of accelerator components R&D’s and on-going construction of a test facility, the Compact ERL.

My wanderings about accelerators started being stimulated by nuclear physics activities of the Kikuchi Laboratory in Osaka University. When the university was founded in 1931, President Nagaoka put emphasis on the nuclear physics programs and called Professor Kikuchi to establish a center of nuclear physics. Since then the laboratory successfully cultivated the new field through studies of the neutron-nucleus interactions with a Cockcroft-Walton accelerator, the beta-decay study with a Cyclotron before the World-War II. Those accelerators were all home made, including the second cyclotron built after the war. Through such experimental programs, the Kikuchi Laboratory brought up many talented physicists in accelerator and nuclear science.

A new type of X-ray source was developed at the Laboratory for Electron Beam Research and Application (LEBRA) in Nihon University. The development was the first case in the world of the X-ray source based on parametric X-ray radiation (PXR) with a dedicated beamline and a double-crystal system. The substantial design and construction was started in 2000 and the first observation of the X-ray beam from the PXR source was achieved in 2004. Since then various studies have been performed to develop the PXR application using its characteristics such as the monochromaticity and the continuous tunability. In particular, the success of dispersive X-ray absorption fine structure analysis and diffraction-based phase-contrast imaging shows good prospects of the PXR application. It is expected that a coherent X-ray source based on PXR will be introduced into medical facilities in the near future.

TILC09–Joint Physics and Detector Workshop and GDE Meeting on International Linear Collider was held at EPOCAL Tsukuba in Japan, where more than 200 researchers attended. It is reported on research and development of ILC accelerator, physics and detectors.