Volpe, L.M. Canova, H.F. Fonseca, P.T. Freitas, P.P.S. Gilmour, A. Rocha, A.S. Rodrigues, G.L.M.P. Sanfelici, L. Saveri Silva, M. Westfahl Jr., H. de Oliveira, H.G.P. JACoW Publishing Geneva, Switzerland 978-3-95450-188-5 10.18429/JACoW-MEDSI2016-WEPE06 English 324-326 WEPE06 ion photon vacuum storage-ring radiation Contribution to a conference proceedings 2017 2017-06 https://doi.org/10.18429/JACoW-MEDSI2016-WEPE06 http://jacow.org/medsi2016/papers/wepe06.pdf Currently under construction on Brazilian Synchrotron Light Laboratory Campus, Campinas/SP, Sirius is a 3GeV, 4th Generation Synchrotron Light Source. In this paper we describe the Front End that has been designed to transmit the intense synchrotron radiation generated by the insertion devices that will generate the most critical thermal stress, with a peak power density of 55.7 kW/mrad² and a total power of 9.3kW at 500mA in the storage ring. The functions of the main components and their location in the layout are described. Computational fluid dynamics (CFD) and structural simulations, that have been carried out to verify the performance under the high heat loads generated by Sirius, are also detailed along with the limits of temperature and stress that have been employed in the design.