Author: Lee, H.-S.
Paper Title Page
WEODB103 Current Status of PAL-XFEL Project 2074
  • H.-S. Kang, J.H. Han, T.-H. Kang, C. Kim, D.E. Kim, S.H. Kim, I.S. Ko, H.-S. Lee, K.-H. Park, S.J. Park
    PAL, Pohang, Kyungbuk, Republic of Korea
  The PAL-XFEL is a 0.1-nm hard X-ray FEL construction project which started from 2011 with a total budget of 400 M$. The PAL-XFEL is designed to have three hard X-ray undulator lines at the end of 10-GeV linac and a dog-leg branch line at 3 GeV point for two soft X-ray undulator lines. The three-bunch compressor lattice (3-BC) is chosen to have large flexibility of operation, making it possible to operate soft X-ray FEL undulator line simultaneously and independently from hard X-ray FEL line. Self seeding to achieve the FEL radiation bandwidth of below 5x10-5 is baseline for the hard X-ray FEL line. Polarization control will be available by using the PU + EPU layout for the soft X-ray FEL line. The overview of the project with current status is presented.  
slides icon Slides WEODB103 [8.332 MB]  
WEPWA043 Construction of Injector Test Facility (ITF) for the PAL XFEL 2220
  • S.J. Park, H. J. Choi, T. Ha, J.H. Han, J.H. Hong, W.H. Hwang, H.-S. Kang, T.-H. Kang, D.T. Kim, J.M. Kim, S.-C. Kim, I.S. Ko, B.H. Lee, H.-S. Lee, W.W. Lee, C.-K. Min, Y.J. Park, Y.G. Son
    PAL, Pohang, Kyungbuk, Republic of Korea
  • M.S. Chae
    POSTECH, Pohang, Kyungbuk, Republic of Korea
  Funding: Work supported by the Ministry of Education, Science and Technology (MEST) in Korea.
An injector test facility (ITF) for the PAL-XFEL has been successfully constructed and its commissioning is under way. The facility is to demonstrate beam performances required by the PAL XFEL (beam energy of 139 MeV, projected rms emittance of < 0.5 mm mrad @ 200 pC, and beam repetition rate of 60 Hz) with good enough stabilities. We have constructed a dedicated building for the facility in which a radiation-shielding tunnel (19.2-m long, 3.5-m wide, and 2.4-m high inner space), a klystron-modulator gallery, a laser room, and a control room are installed. The injector consists of an in-house-developed photo-cathode rf gun, a 30-mJ Ti:Sa laser system, two accelerating structures (as well as two sets of klystron-modulator systems), and various diagnostics as well as magnets & instrumentations. The installation of a transverse deflecting cavity (S-band, 10-fs resolution) and a laser heater is scheduled in 2013. In this article we report on the facility construction and some of the early commisisoning results.
WEPFI043 S-band High Stability Solid State Amplifier for 10 GeV PAL-XFEL 2800
  • W.H. Hwang, J.Y. Huang, H.-S. Kang, H.-S. Lee, W.W. Lee
    PAL, Pohang, Kyungbuk, Republic of Korea
  In PAL, We are constructing a 10GeV PxFEL project. The output power of the klystron is 80 MW at the pulse width of 4 ㎲ and the repetition rate of 60 Hz. And the specifications of the rf phase and amplitude stability are 0.05 degrees(rms) and 0.05%(rms) respectively. The SSA(Solid State Amplifier) is used for driver of 80MW Klystron. The output power of SSA is 800W. Also, the measured rf stability of SSA output is 0.03 degrees rms and 0.025 % rms. This paper describes the microwave system and the SSA for the PxFEL.  
WEPFI044 High Power Test of New SLED System with Biplanar 3-dB Power Divider and Dual Side-wall Coupling Irises for PAL XFEL 2803
  • Y.D. Joo, H. Heo, W.H. Hwang, H.-S. Lee, K.M. Oh, Y.J. Park
    PAL, Pohang, Kyungbuk, Republic of Korea
  The new type of the Stanford Linear Accelerator Energy Doubler (SLED) system for the PAL (Pohang Accelerator Laboratory) XFEL (X-ray Free Electron Laser) is developed to be operated with an RF input power of 80 MW and a pulse width of 4 μs. To prevent the RF breakdown such a high power operation, a biplanar 3-dB power divider and dual side-wall coupling irises structure are used in the new SELD system. It is shown that the field gradient and surface current is reduced from that of the original SLED system using the the finite-difference time-domain (FDTD) simulation. The high power test result of the new SLED system in the PAL XFEL test facility will be presented.  
WEPFI045 PAL-XFEL Accelerating Structures 2806
  • H.-S. Lee, H. Heo, J.Y. Huang, W.H. Hwang, S.D. Jang, Y.D. Joo, H.-S. Kang, I.S. Ko, S.S. Park, Y.J. Park
    PAL, Pohang, Kyungbuk, Republic of Korea
  • I.S. Ko
    POSTECH, Pohang, Kyungbuk, Republic of Korea
  • H. Matsumoto
    KEK, Ibaraki, Japan
  • S.J. Noh, K.M. Oh
    Vitzrotech Co., Ltd., Ansan City, Kyunggi-Do, Republic of Korea
  We need 172 accelerating structures for the PAL-XFEL 10 GeV main linac. It takes long time for these structures to be delivered. So we are trying to find suppliers of the accelerating structures. First, we made an order of 40 accelerating structures to Mitsubishi Heavy Industry (MHI), which have Quasi-type couplers to reduce the quadruple and sextuple components of the electric field in the coupling cavity. And Research Instruments (RI) has fabricated a 3m long race type accelerating structure for PAL-XFEL. Also, Vitzrotech which is a domestic company and IHEP in China are under developing accelerating structures for PAL-XFEL respectively. We will describe the current status of accelerating structures and high power test results of the newly developed structures in this paper.