Construction of the Advanced Detectors for KEK B-factory.

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National Laboratory for High Energy Physics, KEK,is building an asymmetric B-factory. The BELLE detector to study CP violation in B meson decays is under construction. It is expected that the BELLE experiment will provide a definitive test of CP violation in the B-meson system by measuring the three angles and the three sides of the CKM triangles. To realize this goal, a good measurement of B decay vertices and an excellent p/K identification up to 4 GeV/c are necessary. In this project, we studied the optimized design of a Silicon micro-Vertex Detector (SVD) at the B-factory and now build one made of Double-sided Silicon Strip Detectors (DSSD) with a Double-Metal Layr (DML) for the z-strip readout. We designed and tested successfully a large DSSD with DML of wide n-strip pitches, a new 128ch low-noise preamplifier chip (SMAASH chip) with 8 cell analog memory, a new bump-bonding assembly method of detector unit and DAQ-trigger modules. To make the SMAASH chip rediation-hard we test the Rapid Thermal Nitridation (RTN) process, a finer (0.6-0.8 micron) process with a low temperature oxidation. We also plan to try one of established radiation-hard processes DMILL process). As for the p/K separation at the BELLE experiment, we previously performed an intensive R&D study of the fast Ring Image Cherenkov (RICH) counter with a CsI hotocathode. It turned out unfortunately that the quantum efficiency of large CsI photocathodes was not high enough. In this project we made a R&D study of a hybrid phototube and, as a radiator of the Cherenkov light, we developed a new low-index, highly-transparent Silica Aerogel tile. This new aerogel is also higly hydrophobic and easy to handle. We currently prepare a test of a prototype RICH counter consists of the HPT ant the silica aerogel.