Applied Science and Convergence Technology 2015; 24(4): 77-83
Published online July 31, 2015
Copyright © The Korean Vacuum Society.
Heetae Kima*, Yong Sik Changb, Wookang Kima, Yong Woo Joa, and Hyung Jin Kima
aRare Isotope Science Project, Institute for Basic Science, Daejeon 305-811, Korea
bDepartment of e-Business, Hanshin University, Osan 447-791, Korea
Correspondence to:Heetae Kim
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Many welding processes are performed to construct cryogenic system. Leak-tight for the cryogenic system is required at low temperature environment. Helium leak detection techniques are commonly used to find leak for the cryogenic system. The helium leak detection techniques for spraying, sniffing and pressurizing techniques are introduced. High vacuum is also necessary to use helium leak detector. So, types of fluid flow, effective temperature, conductance and pumping speed are introduced for vacuum pumping. Leak test procedure is shown for pipe welding, cryomodule and low temperature test. Cryogenic seals which include copper gasket, helicoflex gasket and indium are investigated.
Keywords: Leak detection, Cryogenic system, Welding, Cryogenic seals, Conductance