Feasibility study of the vacuum design for upgrading the TPS electron storage ring

Gao-Yu Hsiung^1*

¹Instrumentation Development Department, National Synchrotron Radiation Research Center, Hsinchu, Taiwan

* Presenter:Gao-Yu Hsiung, email:hsiung@nsrrc.org.tw

The Taiwan Photon Source (TPS) is a third generation 3 GeV synchrotron light source with low emittance of 1.6 nm·rad, which has been operated since 2015 and achieved a beam current of 500 mA on top-off injection mode. Meanwhile, more new advanced light sources designed with ultralow emittance of < 0.1 nm·rad were constructed for generating much higher brilliant synchrotron light that called the fourth-generation light source. It is feasible to upgrade the TPS from 3rd generation to 4th generation by replacing the vacuum beam ducts of the electron storage ring to suit the requirement of the multi-bend achromatic (MBA) lattice design and the associated strong focusing lattice magnets in the arc-cell bending sections. The aperture of the new beam duct will be smaller than 20 mm, and almost no space between the magnets is allowed for the flanges and the vacuum pumps. To overcome the shortage, the features of the design contain the high thermal conductive aluminum beam ducts with antechamber for photon absorbers and pumping, superior cleaned surface of beam ducts possess the ultralow outgassing rates for the ultrahigh vacuum (UHV) quality, and the smart design of the RF-contact-seal flanges with ultra-low impedance structures of beam ducts for mitigating the wake fields. The conceptual design and the prototype tests will be addressed in this presentation.

Keywords: synchrotron, accelerator, TPS, vacuum, aluminum