Estimation of effective dose caused by stray radiations of photons, electrons and positrons around a small storage ring for a synchrotron radiation facility

The spatial distribution of the effective dose of photons, electrons and positrons caused by beam loss around a small electron storage ring in a synchrotron radiation source is calculated. We propose a simple formula applicable to calculate the effective dose for storage rings for beam energies ranging from 200 MeV to 5 GeV. The formula is derived from Monte Carlo calculations of radiation flux using the simulation code EGS4. We apply the formula to estimate the effective dose distribution in a small synchrotron radiation facility planned by the Nagoya University.