Concept is described on Laser Storage Ring (LSR), or the laser ring resonator composed of toroidal mirrors which have an optical function combining focusing and bending function, plane mirrors and gain mediums. LSR is expected to be a powerful laser beam source useful for such applications as the H^- laser stripping or the laser-Compton-scattered gamma-ray beam source. Experimental results are described to show that a laser ring resonator can be composed using toroidal and plane mirrors. It is also shown that the longitudinal resonance function of the ring resonator is basically same as that of the Fabry‒Perot resonator. LSR using total-internal-reflection toroidal mirrors are proposed.

The compact X-ray source based on Laser-Compton scattering (LCS) has been developed at LUCX (Laser Undulator Compact X-ray source) facility in KEK. The multi-bunch high quality electron beam produced by a standing wave 3.6 cell RF Gun and accelerated by the followed S-band normal conducting 12 cells standing wave “booster” linear accelerator is scattered off the laser beam stored in the optical cavity. The 4-mirror planar optical cavity with finesse 335 is used. The MCP (Micro-Channel Plate) detector as well as SOI (Silicon-On-Insulator) pixel sensor was used for scattered X-ray detection. The SOI pixel sensor has been used for LCS X-ray detection for the first time and has demonstrated high spatial resolution and high SN ratio X-ray detection that in turn lead to clearest X-ray images achieved by LCS X-ray. We have also achieved generation of 6.38 × 10⁶ ph./sec., which is more than 30 times larger LCS X-ray flux in comparison with our previous results. The complete details of LUCX LCS X-ray source, specifications of both electron and laser beams, and the results of LCS X-ray generation experiments are reported in this paper.

Recent advances in accelerator technology and neutronics have made possible the construction of small scale accelerator-driven neutron sources that will be able to play a significant role in future advancements in neutron science and technology. A commercial-based proton linac of 7 MeV and Be target system are under construction at RIKEN. This opens up new opportunities for industrial field using neutron beam.

Upon the discovery of a Higgs like particle at the LHC experiment in July 2012, ideas of various types of Higgs factory were proposed. This workshop, organized by the Beam Dynamics sub-panel of ICFA, aimed to discuss situation and feasibility of all possible types of Higgs factories from a machine technological aspect. In this article, we report discussion in the workshop not being afraid of expressing author’s personal impression.

A public event to celebrate the completion of the Technical Design Report of International Linear Collider was held in Tokyo on December 15 in 2012.