• A. Sheng, C.K. Kuan
  NSRRC, Hsinchu

National Synchrotron Radiation Research Center (NSRRC) will build a new 3GeV, 400mA synchrotron accelerator machine. Several different IDs have been proposed and the corresponding front ends are designed. Beam lines of IU20, IU28, SW48 and EPU70 will be the phase I requirement. Due to different power load and density flux, fixed masks, photon absorber, slits, photon absorber and photon beam position monitor will all be customized to meet the beam line user requirements as well as the thermomechanical limits. Overall front end layout, analysis results of the high heat load components are illustrated; experiments of photon beam position monitor, front end pressure distribution due to thermal and photon stimulated desorption outgassing analysis, are also presented in this paper.

• C.Y. Yang, C.K. Chan, J.-R. Chen, G.-Y. Hsiung, C.K. Kuan, I.C. Sheng
  NSRRC, Hsinchu

Front End (FE) is the first area shapes radiation power to suit the need not only for protection but also for the beam line uses. About 14m long FE vacuum system will connect the ultra high vacuum (UHV) storage ring and beam line in Taiwan Photon Source (TPS). The Fixed mask (FM), photon absorber (PAB) and slit are the major high gas load components, especially in insertion Devices (ID) front ends, because of the synchrotron radiation. From the P(pressure)=Q(outgas)/S(pump) formula, there are some issues will be concerned to get lower vacuum pressure: The low outgassing rate of the vacuum chamber (Qthermal), the localization of the the pumps (IP and NEG) to pump down the outgassing of the photon simulated desorption(Qpsd), and the arrangement of the aperture and gas load . The basic pressure distribution of the bending magnet (BM) and ID front ends will be discussed.