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FEL 2004 26th

Name: FEL 2004 26th

Location: Trieste

Date: 2004-01-01

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Created at: Fri Nov 02 14:06:59 -0700 2007

Updated at: Fri Nov 02 14:06:59 -0700 2007

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5 papers from the conference:

title: Current-Enhanced SASE Using an Optical Laser and its Application to the LCLS
format: conference proceeding
conference: FEL 2004 26th
year: 2004
6 authors: A.A. Zholents | W.M. Fawley | P. Emma | Z. Huang | G. Stupakov | S. Reiche
abstract: We propose a significant enhancement of the electron peak current entering a SASE undulator by inducing an en- ergy modulation in an upstream wiggler magnet via res- onant interaction with an optical laser, followed by mi- crobunching of the energy-modulated electrons at the ac- celerator exit. This current enhancement allows a reduc- tion of the FEL gain length. The x-ray output consists of a series of uniformly spaced spikes, each spike being tem- porally coherent. The duration of this series is controlled by the laser pulse and in principle can be narrowed down to just a single, -attosecond spike. Given potentially absolute temporal synchronization of the x-ray spikes to the energy-modulating laser pulse, this scheme naturally makes pump-probe experiments available to SASE FEL�s. We also study various detrimental effects related to the high electron peak current .
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title: Status Report on SPARC Project
format: conference proceeding
conference: FEL 2004 26th
year: 2004
96 authors: A. Renieri | M. Carpanese | F. Ciocci | G. Dattoli | A. Di Pace | A. Doria | F. Flora | G. P. Gallerano | L. Giannessi | E. Giovenale | G. Messina | L. Mezi | P. L. Ottaviani | S. Pagnutti | G. Parisi | L. Picardi | M. Quattromini | G. Ronci | C. Ronsivalle | E. Sabia | M. Sassi | A. Zucchini | D. Alesini | M. Bellaveglia | S. Bertolucci | M.E. Biagini | C. Biscari | R. Boni | M. Boscolo | M. Castellano | A. Clozza | G. Di Pirro | A. Drago | A. Esposito | M. Ferrario | D. Filippetto | V. Fusco | A. Gallo | A. Ghigo | S. Guiducci | M. Incurvati | C. Ligi | F. Marcellini | M. Migliorati | C. Milardi | L. Palumbo | L. Pellegrino | M. Preger | P. Raimondi | R. Ricci | C. Sanelli | M. Serio | F. Sgamma | B. Spataro | A. Stecchi | A. Stella | F. Tazzioli | C. Vaccarezza | M. Vescovi | C. Vicario | M. Zobov | F. Alessandria | A. Bacci | I. Boscolo | F. Broggi | S. Cialdi | C. De Martinis | D. Giove | C. Maroli | V. Petrillo | M. Romè | L. Serafini | D. Levi | M. Mattioli | G. Medici | P. Musumeci | L. Catani | E. Chiadroni | S. Tazzari | C.J. Bocchetta | M. Danailov | G. D'Auria | M. Ferianis | A. Cianchi | A. D'Angelo | R. Di Salvo | A. Fantini | D. Moricciani | C. Schaerf | S. Reiche | J.B. Rosenzweig | G. Travish | D.H. Dowell | P. Emma | C. Limborg | D. Palmer
abstract: We review the status of FEL source activity of the ongoing SPARC FEL experiment, developed within the framework of a collaboration among ENEA, CNR, INFN, INFM, Sincrotrone Trieste and University of Rome Tor Vergata. The project is aimed at realising a SASE-FEL source, operating in the visible (around 500 nm), with an extended range of tunability down to the VUV (100 nm) by the use of the mechanism of non-linear harmonic generation. The development of the relevant activities foresees the realisation of an advanced 150 MeV photo- injector source, aimed at producing a high brightness electron beams, needed to drive a SASE-FEL experiment, and a 14 m long undulator. We present the status of the design and construction of SPARC FEL device. In particular we discuss the choice of the project parameters, their optimisation and the sensitivity of the SPARC performance to any parameter variation. We will show, using start-to-end simulations, what is the impact of the e- beam and of the undulator parameters on the characteristics of the output laser field and in particular on the amount of the non-linearly generated power at higher harmonics.
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title: Spontaneous Radiation Background Calculation for LCLS
format: conference proceeding
conference: FEL 2004 26th
year: 2004
1 author: S. Reiche
abstract: The intensity of undulator radiation, not amplified by the FEL interaction, can be larger than the maximum FEL sig- nal in the case of an X-ray FEL. In the commissioning of a SASE FEL it is essential to extract an amplified signal early to diagnose eventual misalignment of undulator modules or errors in the undulator field strength. We developed a numerical code to calculate the radiation pattern at any position behind a multi-segmented undulator with arbitrary spacing and field profiles. The output can be run through numerical spatial and frequency filters to model the radiation beam transport and diagnostic. In this presentation we estimate the expected back- ground signal for the FEL diagnostic and at what point along the undulator the FEL signal can be separated from the background. We also discusses how much information on the undulator field and alignment can be obtained from the incoherent radiation signal itself.
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title: Generation of GW-level, sub-Angstrom Radiation in the LCLS using a Second-Harmonic Radiator
format: conference proceeding
conference: FEL 2004 26th
year: 2004
2 authors: Z. Huang | S. Reiche
abstract: Electron beams are strongly microbunched near the high-gain free-electron laser (FEL) saturation with a rich harmonic content in the beam current. While the coherent harmonic emission is possible in a planar undulator, the third- harmonic radiation typically dominates with about 1% of the fundamental power at saturation. In this paper, we discuss the second-harmonic radiation in the Linac Coherent Light Source. We show that by a suitable design of an second- stage undulator with its fundamental frequency tuned to the second harmonic of the first undulator, coherent second-harmonic radiation much more intense than the third-harmonic is emitted. Numerical simulations predict that GW-level, sub- Angstrom x-ray pulses can be generated in a relatively short second-harmonic radiator.
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title: VISA IB: Ultra-High Bandwidth, High Gain SASE FEL
format: conference proceeding
conference: FEL 2004 26th
year: 2004
15 authors: G. Andonian | A. Murokh | R. Agustsson | C. Pellegrini | S. Reiche | J.B. Rosenzweig | G. Travish | M. Babzien | I. Ben-Zvi | J. Y. Huang | V. Litvinenko | V. Yakimenko | M. Ferrario | L. Palumbo | C. Vicario
abstract: We report the results of a high energy spread SASE FEL experiment, the intermediary experiment linking the VISA I and VISA II projects. A highly chirped beam (1.7 %) was transported, without corrections of longitudinal aberrations in the ATF dogleg, and injected into the VISA undulator. The ouput radiation displayed an uncharacteristicly large bandwidth (12 %) with extremely stable lasing and mea- sured energy of about 2 ?J . Start-to-end simulations re- produced key features of the experiment and provided an insight into the michanisms giving rise to such a high band- width. These analyses have important implications on the VISA II experiment.
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