[en] Ethylene-propylene rubber has particular good heat resistance, weather resistance and ozone resistance. It is widely used in automotive rubber parts, rubber sheets, etc. This report describes research on electron beam crosslinking of ethylene-propylene rubber and its application in rubber products. (author)

[en] An innovative solution for high-magnification microscopy, based on attaching afocal optics for focal length reduction, is proposed. The solution, consisting of three spherical mirrors, allows one to enhance a magnification of a laboratory based soft x-ray microscope over 1000x, where movies with diffraction-limited resolution can be observed with an x-ray CCD. The design example, having a numerical aperture of 0.25, was successfully demonstrated both a high magnification and a large field of view.

[en] In order to develop a long-lifetime MCP-PMT under high rates of circumstance, we investigated the degradation of the quantum efficiency (QE) of PMT's with a multialkali photocathode. We found that not only positive ions, but also neutral residual gases would damage the photocathode resulting in an enhancement of the work function; their countermeasures were established in newly manufactured square-shaped MCP-PMT's with 4 or 4 x 4 multi-anodes. The performances of the PMT's were measured: QE was stable up to an integrated amount of anode output charge of 2-3 C/cm², while keeping other basic performances steady, such as the time resolution for single photons (σ_TTS) of ≅40 ps, a photoelectron collection efficiency (CE) of 60%, a multiplication gain (G) of a few x10⁶, and dark counts of 20-300 Hz. The causes of QE degradation are discussed.

[en] CANDLES is the project to search for double beta decay (DBD) of ⁴⁸Ca by using CaF₂ scintillators. The Q-value of ⁴⁸Ca, which is the highest (4.27 MeV) among potential DBD nuclei, is far above energies of γ-rays from natural radioactivities (maximum 2.615 MeV from ²⁰⁸Tl decay), therefore we can naturally expect small backgrounds in the energy region we are interested in. We have constructed the prototype detector, CANDLES III in our laboratory (Osaka U.) at sea level and studied the basic performance of the system, including the light collection, position reconstruction and background rejection. After R and D study we moved the detector system to new experimental room at Kamioka underground laboratory. Herein the expected performances and current status of the CANDLES system are described.