A New PLS-II In-Vacuum Undulator and Characterization of Undulator   Radiation
  This paper describes the result of overall studies from development to characterization of undulator radiation. After three years of upgrading, PLS-II [1, 2] has been operating successfully since 21st March 2012. During the upgrade, we developed and installed an in-vacuum undulator (IVU) that generates brilliant X-ray beam. The IVU with 3 GeV electron beam generates undulator radiation up to ~ 21 keV using 11th higher harmonic. The characterizations of the undulator radiation at an X-ray beam line in PLS-II agreed well with the simulation. Based on this performance demonstration, the in-vacuum undulator is successfully operating at PLS-II. 
D-E. Kim, H-H. Lee, K-H. Park, H-S. Seo, T. Ha, Y-G. Jeong, H-S. Han,   W.W. Lee, J-Y. Huang, S. Nam, K-R. Kim and S. Shin
physics.acc-ph