• S.-Y. Lee, G.W. East, R.W. Ellis, Y.C. Jing, Y. Kim, T.H. Luo, P.D. McChesney, X. Pang, T. Rinckel, P.E. Sokol
  IUCF, Bloomington, Indiana
• J.E. Doskow
  IUCMB, Bloomington, Indiana

We are building a low energy electron storage ring that has many desirable properties, such as varying momentum compaction factor, damping partition numbers, favorable betatron tunes for multiturn accumulations, and excellent dynamic aperture. This storage ring can be used for debunching rf linac beams in one turn, for compression of linac pulses, and more importantly for a compact photon source based on inverse Compton scattering of laser beams.

• Y. Kim, Y.C. Jing, S.-Y. Lee, P.E. Sokol
  IUCF, Bloomington, Indiana

At the Indiana University Cyclotron Facility (IUCF), we are developing a new XFEL concept, which is based on the Compton scattering and the laser undulator instead of the conventional magnetic undulator. Since the period of the laser undulator is only about 500 nm, the coherent hard X-rays can be generated by using a compact electron accelerator with a beam energy of about 50 MeV. In this paper, we report an estimation of the energy spread growths due to the Compton scattering itself and their impacts on the XFEL lasing in the laser undulator based XFEL concept.