undulator

Paper	Title	Other Keywords	Page
PLT03	Energy Recovery Linac Experimental Challenges	linac, photon, emittance, optics	7
	D. H. Bilderback Cornell University, Department of Physics, Ithaca, New York
	ERL projects are ongoing at Jlab, Daresbury, KEK and Cornell. Here we describe the typical experimental concerns of using high-coherence and ultra-fast pulses from the Cornell ERL as an example of a new opportunities. The hi-flux mode is one where the ERL runs at 5 GeV and 100 mA. Many experiments are photon-starved, such as inelastic X-ray scattering. The high-coherence mode is obtained at 25 mA and the transverse emittances could be as low as 8 pm. The beam size will be at its smallest under this operating condition and average spectral brightness as high as 1023 (standard units) are calculated. (WG2 will discuss the ERL accelerator issues.) We expect to produce a 3 micron round emitting source for imaging and coherence experiments on individual biological cells. The ultra-fast mode is one obtained by reducing the repetition rate to 1 MHz and by increasing the bunch charge to 1 nC per pulse and compressing the natural 2 ps bunch length to less than 100 fs. We will present science opportunities for X-ray experiments on a single atom as well as the challenges in optics, other experiments, and beam control issues when making a 1 nm focused X-ray beam size.
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PLT04	Design Considerations for Table-Top FELs	electron, simulation, acceleration, emittance	10
	F. J. Gruener, S. Becker, T. Eichner, D. Habs, U. Schramm, R. Sousa LMU, München M. Geissler, J. Meyer-ter-Vehn MPQ, Garching, Munich S. Reiche UCLA, Los Angeles, California
	Refinements in laser technology (few-cycle pulse generation, chirped pulse amplification) combined with super-computer-based plasma simulations have brought the discipline of relativistic laser-matter interaction to a new level of predictability. This was recently demonstrated by the generation of brilliant electron bunches with energies on the 100-MeV-scale (and supposedly already around 1 GeV). Our plan is to utilize such laser-accelerated electron beams to realize table-top FELs. The essential feature of those electrons is their ultra-high beam current of up to few 100 kA in 10 fs. Such high currents make small-period undulators realistic, which require less electron energy for the same FEL wavelength. Together with low emittance and relatively large Pierce parameter the undulator length for reaching SASE saturation should be as small as only meter-scales. In this paper we present our first basic design considerations based upon start-to-end simulations including 3d PIC codes and GENESIS 1.3. In contrast to the large-scale XFELs, which will be dedicated user facilities, our aim is just to deliver the proof-of-principle of table-top FELs, starting from the VUV to the X-ray range.
	Slides