T. Shintomi

LARGE-SCALE CRYOGENIC GRAVITATIONAL WAVE TELESCOPE

We present here the Large-scale Cryogenic Gravitational wave Telescope (LCGT) project which is aimed to improve the sensitivity of the existing gravitational wave projects by ten times. LCGT is the project constructing the km-scale gravitational wave detector in Japan succeeding the TAMA project, which adopts cryogenic mirrors with a higher power laser. We are planing to build it in an underground site in Kamioka mine. If its target sensitivity is attained, we will be able to catch a few events per month.

The superconducting kaon spectrometer — SKS

A superconducting kaon spectrometer has been installed in the north experimental hall of the KEK 12-GeV proton synchrotron. The spectrometer was designed to serve for nuclear physics experiments with meson beams in the 1 GeV/c region, particular emphasis being laid on study of Λ-hypernuclei via (π+, K+) reactions. In order to obtain Λ-hypernuclear data with better statistics and energy resolution, it was designed to have a good momentum resolution of 0.1% FWHM and a large acceptance of 100 msr. It consists of a large superconducting dipole magnet, tracking chambers, and trigger counters that can efficiently select kaons from large background of pions and protons. The overall energy resolution for scattering is realized together with a beam-line spectrometer in the K6 beam line, the momentum resolution of which was also designed to be better than 0.1% FWHM. A good energy resolution of better than 2 MeV FWHM has been confirmed in π−-12C elastic scattering and in the (π+,K+) reaction on 12C.

CRYOGENIC COOLING OF A SAPPHIRE MIRROR-SUSPENSION FOR INTERFEROMETRIC GRAVITATIONAL WAVE DETECTORS

Abstract The sensitivity of large-scale interferometric gravitational wave detectors currently under construction will be limited by thermal noise in the mirror-suspension system. Cryogenic cooling is made difficult because of the necessarily high laser power (5 kW) incident on the mirrors. An all sapphire system of high conductivity and low loss has been developed. Experiments confirm that mirrors for the TAMA detector could be cooled to as low as 14.5 K. This represents two orders of magnitude reduction in the mirror-suspension thermal noise energy.

Design study of a superconducting insertion quadrupole magnet for the Large Hadron Collider

The conceptual design study of a high gradient superconducting insertion quadrupole magnet has been carried out in collaboration between KEK and CERN for the Large Hadron Collider (LHC) to be built at CERN. A model magnet design has been optimized to provide a nominal design field gradient of 240 T/m with a bore aperture of 70 mm and an operational field gradient of 225 T/m at 1.9 K under radiation environment with a deposition of several watts per meter in the superconducting coils. The design and its process are discussed.

Measurement of the mechanical loss of a cooled reflective coating for gravitational wave detection

We have measured the mechanical loss of a dielectric multilayer reflective coating (ion-beam sputtered

Progress of LHC low-/spl beta/ quadrupole magnets at KEK

{\mathrm{SiO}}_{2}

Present status of large-scale cryogenic gravitational wave telescope

and

Reduction of thermal fluctuations in a cryogenic laser interferometric gravitational wave detector.

{\mathrm{Ta}}_{2}{\mathrm{O}}_{5}

The CLIO project

) in cooled mirrors. The loss was nearly independent of the temperature (

Magnetic design of a low-/spl beta/ quadrupole magnet for the LHC interaction regions

4\text{ }\text{ }\mathrm{K}\ensuremath{\sim}300\text{ }\text{ }\mathrm{K}