Front-end components for SPring-8 insertion devices: finite-element analysis for a heat absorber

SPring-8 is a third generation synchrotron facility that provides high-brilliance synchrotron radiations in the x ray region. The electron or positron beam with an energy of 8 GeV is stored up to 100 mA in the storage ring with a circumference of 1,435.95 m. Of 44 straight sections in the storage ring, 38 straight sections are available for insertion device beamlines. The insertion devices installed in the 8 GeV storage ring produce higher total power and power density compared with those in the 2 - 3 GeV storage rings since the total power is proportional to the square of the stored electron or positron energy and the aperture of the radiation cone is inversely proportional to the electron or positron energy. Such substantial amounts of heat power radiated from the undulator and wiggler are deposited on the components of the front-end. The heat absorber intercepts the synchrotron radiation beams to protect front-end components placed downstream. In this work, we have studied the heat absorber in the insertion device front-end by the finite element analysis.