X-Ray Absorber Design and Calculations for the EBS Storage Ring

International audienceThe Extremely Brilliant Source (EBS) of the ESRF will hold new type of X-Ray absorbers: a new material will be used (CuCr1Zr suggested by *) together with a novel design integrating: - CF flange are machined in the absorber body. No weld, no braze. - Optimized toothed surface profile, reducing the induced thermal stresses. - Compton and Rayleigh scattering integrated blocking shapes. - Concentric cooling channels. A brief overview of the new design and concepts will be given. The presentation will then focus on thermo-mechanical absorber ANSYS calculations, combining both Computational Fluid Mechanics (CFD). The calculations and the calculation process will be discussed as well as the design criteria chosen by the team. The CFD calculations will show that an heat transfer coefficient between the water and the copper part can be estimated as well as the pressure drop through the absorber. Finally, the stress analysis will be emphasized. The type of stresses (tensile, compressive or shear) and their nature (primary or secondary) will be linked to the choice of design criteria

Stainless Steel Vacuum Chambers for the EBS Storage Ring

International audienceThe upgrade of the ESRF (ESRF-EBS) is a highly challenging project in many respects. One major challenge is to manufacture vacuum chambers within extremely tight tolerances. Indeed the chamber envelope is constrained by the very limited space available between the beam stay clear and the magnets pole tips, requiring profile tolerances of just 500 um over the full length of the chamber for a width of 55 mm. An additional challenge is guaranteeing the perpendicularity (up to 0.75 mrad) between the CF flanges and the chamber body. While a design using discrete removable absorbers was chosen, one family of chambers contains a distributed absorber required to protect the insertion devices from 600 W of upstream dipole X-rays. Two companies have been selected to produce a total of 296 stainless steel chambers. Given the unusual tolerance requirements, the manufacturers have been obliged to adapt and develop their production techniques to overcome the challenges. During manufacture, vacuum leaks were discovered on some of the BPM buttons. This paper will also present the two techniques that ESRF has developed in order to prevent the integration of potentially leaking buttons

Thermal Stability of the New ESRF Extremely Brilliant Source

International audienceIn the frame of the Extremely Brilliant Source project (EBS), studies dedicated to disturbances have been more intensively investigated. Engineering instabilities have two origins: mechanical and thermal. Major thermal issues are: - air conditioning presents a temperature ramp up of 2°C along the sector - storage ring requires a warm up period of 4 days for reaching a stable orbit These effects have been observed and corrected for 20 years. With EBS requirements, we need to identify these thermal effects in order to reduce the disturbances, thus improving more systematically the source stability. The study is lead by the comparison between the present and the new thermal system. To do so, it is necessary to evaluate the heat balance in this system, as well as to identify the thermal time constant of each component. FEA models have been performed to reveal sensitivity of these thermal issues. A full scale mock-up cell equipped with a prototype girder is measured with power cables inside. A FEA model was also developed for the present storage ring to analyse the air stream. Although investigations have already been developed, some others remain to be achieved by the end of 2016

ESRF Operation Status

International audienceThe European Synchrotron Radiation Facility (ESRF) is undergoing the second phase (2015-2022) of an Up-grade which concerns its infrastructure, beamlines and X-ray source. This paper reports on the present operational source performance, highlighting the most recent developments, and the preparation of the Extremely Brilliant Source project. The renovation of the injector and the recent operation in top-up mode are also detailed