A mid-infrared oscillator FEL has been commissioned at the Fritz Haber Institute. The accelerator consists of a thermionic gridded gun, a subharmonic buncher, and two S-band standing-wave copper structures. It provides a final electron energy adjustable from 15 to 50 MeV, low longitudinal (< 50 keV ps) and transverse emittance (< 20 πmm mrad), at more than 200 pC bunch charge with a micro-pulse repetition rate of 1 GHz and a macro-pulse length of up to 15 <i>µ</i>s. Pulsed radiation with up to 100 mJ macro-pulse energy at about 0.5% FWHM bandwidth is routinely produced in the wavelength range from 4 to 48 <i>µ</i>m. A characterization of the FEL performance in terms of pulse energy, bandwidth, and micro-pulse shape of the IR radiation is given. In addition, selected user results are presented. These include, for instance, spectroscopy of bio-molecules (peptides and small proteins) either conformer selected by ion mobility spectrometry or embedded in superfluid helium nano-droplets at 0.4 K, as well as vibrational spectroscopy of mass-selected metal-oxide clusters and protonated water clusters in the gas phase.
Next generation x-ray sources require very high-brightness electron beams that are typically at or beyond the present state-of-the-art, and thus place stringent and demanding requirements upon the electron injector parameters. No one electron source concept is suitable for all the diverse applications envisaged, which have operating characteristics ranging from high-average-current, quasi-CW, to high-peak-current, single-pulse electron beams. Advanced Energy Systems, in collaboration with various partners, is developing several electron injector concepts for these x-ray source applications. The performance and design characteristics of five specific RF injectors, spanning "L" to "X"-band, normal-conducting to superconducting, and low repetition rate to CW, which are presently in various stages of design, construction or testing, is described. We also discuss the status and schedule of each with respect to testing.
This is a facility report of the J. Bennett Johnston, Sr., Center for Advanced Microstructures and Devices, a new synchrotron-radiation laboratory at Louisiana State University. The accelerator system is described and the radiation characteristics are presented and compared with hypothetical ultra-bright synchrotron sources. The comparison is made to demonstrate the utility of a second-generation `work horse' in the world of the new very-low-emittance machines. In addition to these technical parameters, a brief history of the Center and an overview of the program are presented.