• S.J. Russell, K. Bishofberger, B.E. Carlsten, D.C. Nguyen, E.I. Simakov
  LANL, Los Alamos, New Mexico

At Los Alamos National Laboratory we are actively exploring the feasibility of constructing a 50-keV x-ray free-electron laser. For such a machine to be feasible, we need to limit the cost and size of the accelerator and, as this is intended as a user facility, we would prefer to use proven, conventional accelerator technology. Using recent developments in transverse-to-transverse and transverse-to-longitudinal emittance exchange optics *, **, we present a conceptual 20-GeV conventional electron accelerator design capable of producing an electron beam with a normalized transverse emittance as low as 0.2 mm-mrad, a root-mean-square (RMS) beam length of 74 fs, and an RMS energy spread of 0.01%. We also explore the possibility of introducing a crystallographic mask into the beam line. Combined with a transverse-to-longitudinal emittance exchange optic, we show that such a mask can be used to modulate the electron beam longitudinally to match the x-ray wavelength. This modulation, combined with the very low transverse beam emittance, allows us to not only generate 50-keV x-rays with a 20-GeV electron beam, but also drastically decrease the length of the required undulator.

*P. Emma, Z. Huang, K. -J. Kim, and P. Piot, Phys. Rev. ST Accel. Beams 9, 100702 (2006).
**B. E. Carlsten and K. A. Bishofberger, New J. Phys. 8, 286 (2006).

• A. Adelmann, Y. Ineichen, C. Kraus, T. Schietinger
  PSI, Villigen
• S.J. Russell
  LANL, Los Alamos, New Mexico
• J.J. Yang
  CIAE, Beijing

OPAL (Object Oriented Parallel Accelerator Library) is a tool for charged-particle optics in accelerator structures and beam lines including 3D space charge, short range wake-fields and a 1D coherent synchrotron radiation. Built from first principles as a parallel application, OPAL admits simulations of any scale, from the laptop to the largest HPC clusters available today. Simulations, in particular HPC (High Performance Computing) simulations, form the third pillar of science, complementing theory and experiment. In this paper we present numerical and HPC capabilities such as fast direct and iterative solvers together with timings up to several thousands of processors. The application of OPAL to our PSI-XFEL project as well as to the ongoing high power cyclotron upgrade will demonstrate OPAL's capabilities applied to ongoing projects at PSI. Plans for future developments will be discussed.