Ultrahigh Vacuum Technologies Developed for a Large Aluminum Accelerator Vacuum System

Title & Authors
Ultrahigh Vacuum Technologies Developed for a Large Aluminum Accelerator Vacuum System
Hsiung, G.Y.; Chang, C.C.; Yang, Y.C.; Chang, C.H.; Hsueh, H.P.; Hsu, S.N.; Chen, J.R.;

Abstract
A large particle accelerator requires an ultrahigh vacuum (UHV) system of average pressure under $\small{1{\times}10^{-7}}$ Pa for mitigating the impact of beam scattering from the residual gas molecules. The surface inside the beam ducts should be controlled with an extremely low thermal outgassing rate under $\small{1{\times}10^{-9}Pa{\cdot}m^3/(s{\cdot}m^2)}$ for the sake of the insufficient pumping speed. To fulfil the requirements, the aluminum alloys were adopted as the materials of the beam ducts for large accelerator that thanks to the good features of higher thermal conductivity, non-radioactivity, non-magnetism, precise machining capability, et al. To put the aluminum into the large accelerator vacuum systems, several key technologies have been developed will be introduced. The concepts contain the precise computer numerical control (CNC) machining process for the large aluminum ducts and parts in pure alcohol and in an oil-free environment, surface cleaning with ozonized water, stringent welding process control manually or automatically to form a large sector of aluminum ducts, ex-situ baking process to reach UHV and sealed for transportation and installation, UHV pumping with the sputtering ion pumps and the non-evaporable getters (NEG), et al. The developed UHV technologies have been applied to the 3 GeV Taiwan Photon Source (TPS) and revealed good results as the expectation. The problems of leakage encountered during the assembling were most associated with the vacuum baking which result in the consequent trouble shootings and more times of baking. Then the installation of the well-sealed UHV systems is recommended.
Keywords
Ultrahigh vacuum;Accelerator;Aluminum;Outgassing rate;Ozonized water;Oil-free machining;
Language
English
Cited by
1.
Introduction to Helium Leak Detection Techniques for Cryogenic Systems,;;;;;

Applied Science and Convergence Technology, 2015. vol.24. 4, pp.77-83
2.
Vacuum Test of Cavity with Liquid Nitrogen,;;;

Applied Science and Convergence Technology, 2015. vol.24. 5, pp.132-135
1.
Replacement of the TPS bending chamber with an on-site cutting method, Vacuum, 2017, 143, 229
2.
Vacuum Test of Cavity with Liquid Nitrogen, Applied Science and Convergence Technology, 2015, 24, 5, 132
3.
Introduction to Helium Leak Detection Techniques for Cryogenic Systems, Applied Science and Convergence Technology, 2015, 24, 4, 77
4.
Conditioning of the vacuum system of the TPS storage ring without baking in situ, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2017, 851, 57
References
1.
A. Roth, "Vacuum Technology", 3rd edition, Elsevier Science B.V., (1990).

2.
G. Y. Hsiung, C. K. Chan, C. C. Chang, H. P. Hsueh, Z. D. Tsai, and J. R. Chen, "Vacuum Design of the TPS Relates to the Beam Effects", Proceedings of EPAC08, THPP143, 3699 (2008).

3.
G. Y. Hsiung, C. K. Chan, H. P. Hsueh, T. L. Yang, C. K. Kuan, C. C. Chang, S. N. Hsu, C. Y. Yang, C. L. Chen, and J. R. Chen, "Design of the Aluminum Vacuum Chambers for the 3 GeV TPS Electron Storage Ring", AIP Conf. Proc. 879, 62 (2007).

4.
G. Y. Hsiung, C. K. Chan, C. C. Chang, C. L. Chen, S. N. Hsu, H. P. Hsueh, Albert Sheng, C. Y. Yang, Y. B. Chen, and J. R. Chen, "TPS VACUUM SYSTEM", Proceedings of PAC09, MO6RFP018, 387 (2009).

5.
G. Y. Hsiung, C. K. Chan, C. C. Chang, C. L. Chen, C. M. Cheng, Y. T. Cheng, S. N. Hsu, H. P. Hsueh, Yingtzu Huang, Albert Sheng, L. H. Wu, Y. C. Yang, and J. R. Chen, "Optimization of the Ultra-high Vacuum Systems for the 3 GeV TPS Synchrotron Light Source", Proceedings of IPAC2012, WEPPD021, 2543 (2012).

6.
J. R. Chen, G. Y. Hsiung, C. C. Chang, C. L. Chen, C. K. Chan, C. M. Cheng, C. Y. Yang, L. H. Wu, and H. P. Hsueh, "Vacuum system of the 3 GeV Taiwan photon source", J. Vac. Sci. Technol. A28(4), 942 (2010).

7.
C. C. Chang, C. L. Chen, C. K. Chan, S. N. Hsu, G. Y. Hsiung, and J. R. Chen, "Manufacturing and welding process of straight section of aluminum alloy UHV chambers for Taiwan Photon Source", Proceedings of IPAC2012, WEPPD019, (2012).

8.
H. P. Hsueh, C. K. Chan, C. H. Chang, C. C. Chang, C. L. Chen, C. M. Cheng, Y. T. Cheng, G. Y. Hsiung, S. N. Hsu, C. S. Huang, I. T. Huang, T. Y. Lee, H. Y. Yan, Y. C. Yang, and J. R. Chen, "The Installation of One 14 Meter Cell of TPS Vacuum System", Proceedings of IPAC2011, TUPS031, 1599 (2011).

9.
G. Y. Hsiung, C. C. Chang, C. L. Chen, L. H. Wu, C. M. Cheng, C. K. Chan, Y. C. Yang, H. P. Hsueh, S. N. Hsu, and J. R. Chen, " Aluminium ultrahigh vacuum system for the 3 GeV TPS synchrotron light source", Journal of Physics: Conference Series 439, 012034 (2013).

10.
G. Y. Hsiung, H. P. Hsueh, Y. T. Huang, C. M. Cheng, Y. C. Yang, C. K. Chan, L. H. Wu, C. H. Chang, C. S. Huang, S. W. Chang, T. Y. Lee, Y. P. Chang, Z. W. Chen, Y. T. Cheng, S. N. Hsu, C. C. Chang, C. L. Chen, and J. R. Chen, "Construction Status of the TPS Vacuum Systems", Proceedings of IPAC2013, THPFI077, 3472 (2013).

11.
L. H. Wu, T. Y. Lee, G. Y. Hsiung, Y. C. Yang, Z. W. Chen, Y. P. Chang, C. S. Huang, Y. T. Huang, C. H. Chang, S. W. Chang, C. C. Chang, S. N. Hsu, Y. T. Cheng, C. K. Chan, C. M. Cheng, B. Y. Chen, H. P. Hsueh, and J. R. Chen, "Study of the ultra-high-vacuum system of the 14-m-long vacuum chamber of the Taiwan Photon Source using the pressure build-up method", VACUUM 109, 368 (2014).