Upgrade of Pohang Light Source (PLS-II) and Challenge to PAL XFEL

In December 10, 2010, the Pohang Light Source (PLS) permanently stopped its operation. The PLS was the first third-generation light source in Korea and operated for 15 years. The PLS energy was 2.5 GeV. With strong user requests to increase the number of high-quality insertion device (ID) beamlines and to further improve beam quality of the PLS, the Pohang Accelerator Laboratory (PAL) started a new project in 2009 to convert the old PLS to a new and advanced third-generation light source, PLS-II [1 Nam, S. H. Proc. PAC'09. Vancouver, Canada. pp.3172–3174. [Google Scholar]]. The PLS-II project period and budget were three years from 2009 and US $100 M. The project was successfully completed on time and within budget in 2011. The PLS-II fully opened its door to users on March 21, 2012.