Gao-Yu Hsiung

An aluminum vacuum chamber for the bending magnet of the SRRC synchrotron light source

Abstract A bending magnet vacuum chamber of the SRRC synchrotron light source has been studied. The A6061-T6 aluminum alloy was chosen as the chamber material, and a numerical-controlled oil-less machining process was applied for the fabrication. The AES and SIMS surface analysis methods have been applied to analyse the contaminations on the surface of this chamber. After a TIG welding process, the deformation of this chamber was ⪅ 0.3 mm per meter length. The ‘concentrated’ pumping method was designed and a distributed ion pump was also built in this chamber. A static vacuum of ⩽ 1 × 10 −10 torr has been reached after a bakeout of 150°C. In addition to the above-mentioned works, the residual gases of the system and the pumping speeds of the distributed ion pump were also measured.

Measurement of the Pressure in the TPS Booster Ring

The booster ring of Taiwan Photon Source (TPS) is designed to provide full energy injection 3 GeV ramped up from 150 MeV with a small beam emittance. It is a synchrotron accelerator of circumference 496.8 m. The vacuum chamber through the magnets is made of thin stainless-steel tube extruded to an elliptical cross section of inner diameters 35 mm and 20 mm, and thickness 0.7 mm. The other chambers have standard 35CF round tube. The vacuum system was baked in the first installation. Because the residual stress of the stainless-steel elliptical tubing caused the magnetic field to become unstable, all elliptical tubing was removed for annealing to proceed, and reinstalled without baking. The ultimate pressure and data for the residual gas are shown as follows.

The Installation of TPS Booster Vacuum System

The booster of Taiwan Photon Source (TPS) is designed for 3GeV full energy injection ramped up from 150MeV. It is a synchrotron accelerator of 496.8m. The major vacuum system is elliptical tube made of SUS304 stainless steel. The inner cross section is 35*20 mm with 0.7 mm thickness. The elliptical tubes were chemical cleaned and ozonated water cleaned before installation. The bending tube was assembled and aligned into dipole magnet at laboratory. The BPM support and pumping chamber support was aligned with 0.3 mm deviation. The BPM chamber and pumping chamber was assembled firstly. The elliptical tube and bellows was installed to connect BPM, pumping chamber and bending chamber. The cold cathode gauge and TMP was mounted on pumping chamber. The pressure data and residual gas analysis will be described in the paper.

Development of X-ray Beam Position Monitors for Superconducting Wiggler

For the development of an X‐ray beam position monitor (XBPM) for the superconducting wiggler (SW) at the NSRRC, two XBPM are installed in the SW front end. The blades of the XBPM were manufactured with material of three types; tungsten, Glidcop and aluminium, to test the effect of the material on the performance of the XBPM. These three materials are compared with blades of molybdenum that were previously installed. The vibration and thermal expansion of the pillar of a XBPM affects the position reading of the XBPM. For pillars of XBPM of various designs, each type has a distinct thermal isolating material and is filled with a separate damping material for comparison. The design requirements of these XBPM include high spatial resolution of the monitor and mechanical stability of the structure with a large thermal load. The design, fabrication and measurement results are presented here.