Leakage dose distribution due to scattered photon of synchrotron radiation from concrete floor of beamline hutch

The leakage doses due to scattered photon from the concrete floor of the synchrotron radiation beamline hutch, so called ground shine, have been calculated by using a general purpose gamma-ray scattering code G33-GP2 for it ranging from 30 keV to 2.5 MeV. Calculations were performed for three geometries, the geometries with lead bands equipped along the foot of the inside and outside the hutch wall, and that with the bottom part of hutch wall buried in the concrete floor. Validity of the calculation was verified by comparing its calculation with those using a Monte Carlo code ITS3.0. The total leakage dose outside the hutch has been estimated for the case of the typical wiggler, undulator and bending-magnet beamlines of SPring-8, showing that the dose due to ground shine is found to be a serious issue for the 8 GeV class synchrotron radiation beamline and that the lead band set along the foot of the outside hutch is found to be the most beneficial for shielding the ground shine. (author)