Conception design for radiation monitors of SPring-8 in Japan

SPring-8 (Super Photon ring-8 GeV) in JAPAN is the world's most powerful third-generation synchrotron radiation facility. The construction of the facility began in 1991, at Harima Science Garden City in Hyogo-ken, jointly by Japan Atomic Energy Research Institute (JAERI) and Institute of Physical and Chemical Research (RIKEN). The facility produced the first synchrotron radiation in March 1997, and user beam operation was started from October 1997. SPring-8 mainly consists of Linac (Linear Accelerator), Synchrotron (Booster synchrotron), Storage Ring and Beamlines. Linac generates electrons with electron gun and accelerates them to an energy of 1 GeV. Accelerated electrons are injected into Synchrotron and their energy is increased to 8 GeV. Storage Ring stores the electrons of 8 GeV and generates the synchrotron radiation. The synchrotron radiation is transported by beam lines and used in the experimental Hutches. In this presentation, as JAERI Health Physics Staffs concerned to a starting design on a Radiation Monitoring System in the Accelerator System of SPring-8, we report some examinations with relation to radiation properties on detectors, arrangement to monitors, etc. The important results of development is a low background and high efficiency exhaust gas monitor, and also it made both improvement for properties of radiation pulse width response and a measurement data from a log amplifier for the ionization chamber. (author)