Current Status of PAL-XFEL Project

The PAL-XFEL, a 0.1-nm hard X-ray FEL facility consisting of a 10-GeV S-band linac, is being constructed in Pohang, South Korea. The installation of linac, undulator, and beam line will be completed by 2015. Its building construction is at its peak moment to be completed by December 2014. The major procurement contract was made in 2013 for the critical components of S-band linac modules and hard X-ray undulators. The commissioning will start in January 2016. We hope the first lasing will be achieved in early 2016. CONSTRUCTION STATUS AND SCHEDULE The PAL-XFEL project started in April 2011 is expected to be completed by 2015. It will include a 10GeV linac consisting of a photocathode RF gun, 51 klystrons and modulators, 174 accelerating structures, three bunch compressors, one X-band system for RF linearization, and various diagnostic devices. Beyond the 10-GeV linac, a 240-m long undulator hall follows, where three undulator chains will be installed. However, the current budget will cover only one undulator chain. An experimental area 60-meters long and 16-meters wide is located at the end of the facility. The total length of the building is 1,110 meters[1]. Building construction started in September 2012. Since then, 1.2 million cubic meters of soil have been removed, and the concrete shielding of the machine tunnel is completed. It is expected that the building will be ready for use by November 2014. Fig. 1 shows the current status of building construction at the PAL site. Installation of the linac, undulator system, and beamlines will start when the beneficial occupancy of the building is available in fall 2014, and will be completed by the end of 2015. Figure 1: Construction site of PAL-XFEL. Figure 2 shows the undulator lines for Phase-1 of PALXFEL. Two undulator lines, a hard X-ray FEL line (HX1) and a soft X-ray FEL line (SX1), will be completed by 2015. HX1 will cover the wavelength of =0.06 0.6 nm, and use linear polarization, variable gap, out-vacuum undulators. The operation mode is SASE for Phase-1, self-seeded for Phase-2. SX1 will cover the wavelength of = 1.0 4.5 nm. Polarization control is linear for Phase-1, and variable for Phase-2 using two sets of EPU. An enough space for undulators is reserved for future upgrade to house a total of 29 undulators (180 m) for HX1 (18 undulators for Phase-1) and a total of 16 undulators (96 m) for SX1 (8 undulators, 6 PU + 2 EPU). Figure 2: Undulator lines for phase-1 of PAL-XFEL. Linac RF conditioning and Injector commissioning are scheduled in October to December 2015. The first XFEL commissioning is scheduled in early 2016 aiming for 0.3nm radiation with 6-GeV beam at 10 Hz for HX1. The 2nd FEL commissioning is scheduled in September to December 2016 for 0.1 nm HX and 3 nm SX at 10Hz.