| Paper |
Title |
Page |
| MOPPH031 |
The Saturated Regime of a Seeded Single-Pass Free Electron Laser: a Theoretical Investigation through the Statistical Mechanics of the Vlasov Equation
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103 |
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- F. Curbis, F. Curbis
Università degli Studi di Trieste, Trieste
- A. Antoniazzi, D. Fanelli
Università di Firenze, Florence
- G. De Ninno
ELETTRA, Basovizza, Trieste
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The quasi-stationary state characterizing the saturation of a single-pass free-electron laser is governed by the Vlasov equation obtained by performing the continuum limit of the Colson-Bonifacio model. By means of a statistical treatment, this approach allows to predict analytically the saturated laser intensity as well as the final electron-beam energy distribution. In this paper we consider the case of coherent harmonic generation obtained from a seeded free-electron laser and present predictions for the first stage of the project FERMI at Elettra project at Sincrotrone Trieste.
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| MOPPH031 |
The Saturated Regime of a Seeded Single-Pass Free Electron Laser: a Theoretical Investigation through the Statistical Mechanics of the Vlasov Equation
|
103 |
| |
- F. Curbis, F. Curbis
Università degli Studi di Trieste, Trieste
- A. Antoniazzi, D. Fanelli
Università di Firenze, Florence
- G. De Ninno
ELETTRA, Basovizza, Trieste
|
|
| |
The quasi-stationary state characterizing the saturation of a single-pass free-electron laser is governed by the Vlasov equation obtained by performing the continuum limit of the Colson-Bonifacio model. By means of a statistical treatment, this approach allows to predict analytically the saturated laser intensity as well as the final electron-beam energy distribution. In this paper we consider the case of coherent harmonic generation obtained from a seeded free-electron laser and present predictions for the first stage of the project FERMI at Elettra project at Sincrotrone Trieste.
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| MOPPH055 |
Coherent Harmonic Emission of the Elettra Storage-Ring Free-Electron Laser in Single-Pass Configuration: a Numerical Study for Different Undulator Polarizations
|
170 |
| |
- F. Curbis, F. Curbis
Università degli Studi di Trieste, Trieste
- G. De Ninno
ELETTRA, Basovizza, Trieste
- H. Freund
SAIC, McLean
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| |
The optical klystron installed on the Elettra storage-ring is normally used as interaction region for an oscillator free-electron laser, but, removing the optical cavity and using an external seed laser, one obtains an effective scheme for the single-pass harmonic generation. In this configuration, which is presently under development, the high-power external laser is synchronized with the electron beam entering the first undulator of the optical klystron. The laser-electron beam interaction produces a spatial partition of electrons in micro-bunches separated by the seed wavelength. The micro-bunching is then exploited in the second undulator (radiator) to produce coherent light at the harmonics of the seed wavelength. The Elettra radiator is an APPLE type undulator and this allows to explore different configurations of polarization. We present here numerical results obtained using the code Medusa for both planar and helical configurations. We also draw a comparison with predictions of the numerical code Genesis.
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| MOPPH055 |
Coherent Harmonic Emission of the Elettra Storage-Ring Free-Electron Laser in Single-Pass Configuration: a Numerical Study for Different Undulator Polarizations
|
170 |
| |
- F. Curbis, F. Curbis
Università degli Studi di Trieste, Trieste
- G. De Ninno
ELETTRA, Basovizza, Trieste
- H. Freund
SAIC, McLean
|
|
| |
The optical klystron installed on the Elettra storage-ring is normally used as interaction region for an oscillator free-electron laser, but, removing the optical cavity and using an external seed laser, one obtains an effective scheme for the single-pass harmonic generation. In this configuration, which is presently under development, the high-power external laser is synchronized with the electron beam entering the first undulator of the optical klystron. The laser-electron beam interaction produces a spatial partition of electrons in micro-bunches separated by the seed wavelength. The micro-bunching is then exploited in the second undulator (radiator) to produce coherent light at the harmonics of the seed wavelength. The Elettra radiator is an APPLE type undulator and this allows to explore different configurations of polarization. We present here numerical results obtained using the code Medusa for both planar and helical configurations. We also draw a comparison with predictions of the numerical code Genesis.
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| TUPPH021 |
Q-Switch Techniques Implemented at the ELETTRA Storage-Ring Free Electron Laser
|
360 |
| |
- F. Curbis, F. Curbis
Università degli Studi di Trieste, Trieste
- M. B. Danailov, G. De Ninno, B. Diviacco, L. Romanzin, M. Trovo
ELETTRA, Basovizza, Trieste
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In a storage-ring FEL the gain can be calculated measuring the rise-time of giant pulses, produced by the interaction between the light stored in the optical cavity and an electron beam with low energy-spread (cold beam). This interplay produces the heating of the beam. Therefore, after the generation of a single giant pulse, the overlap between electrons and radiation is periodically prevented for a time necessary to dump the energy spread and recover the cold-beam condition. For this purpose two different methods are implemented at Elettra. In the first, modifying the radio-frequency of the ring, the change of the revolution time of electrons avoids the temporal overlap between the electron beam and the optical field in the mirror cavity. The second method relies on a mechanical gating (chopper) which intercept the light produced during previous interactions, inducing a periodic emptying of the optical cavity. The gain can be also estimated using an indirect formula after measuring the electron-beam energy spread and bunch length. In this paper we compare the different techniques mentioned above for the case of the Elettra SR-FEL.
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| TUPPH021 |
Q-Switch Techniques Implemented at the ELETTRA Storage-Ring Free Electron Laser
|
360 |
| |
- F. Curbis, F. Curbis
Università degli Studi di Trieste, Trieste
- M. B. Danailov, G. De Ninno, B. Diviacco, L. Romanzin, M. Trovo
ELETTRA, Basovizza, Trieste
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| |
In a storage-ring FEL the gain can be calculated measuring the rise-time of giant pulses, produced by the interaction between the light stored in the optical cavity and an electron beam with low energy-spread (cold beam). This interplay produces the heating of the beam. Therefore, after the generation of a single giant pulse, the overlap between electrons and radiation is periodically prevented for a time necessary to dump the energy spread and recover the cold-beam condition. For this purpose two different methods are implemented at Elettra. In the first, modifying the radio-frequency of the ring, the change of the revolution time of electrons avoids the temporal overlap between the electron beam and the optical field in the mirror cavity. The second method relies on a mechanical gating (chopper) which intercept the light produced during previous interactions, inducing a periodic emptying of the optical cavity. The gain can be also estimated using an indirect formula after measuring the electron-beam energy spread and bunch length. In this paper we compare the different techniques mentioned above for the case of the Elettra SR-FEL.
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| TUPPH044 |
Free Electron Laser Study of Free Carbon Clusters
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423 |
| |
- C. Spezzani, E. Allaria, F. Curbis, G. De Ninno, B. Diviacco, L. Romanzin, S. Tileva, M. Trovo
ELETTRA, Basovizza, Trieste
- M. Amati, G. Bongiorno, C. Lenardi, T. Mazza, P. Milani, T. A. Mostefaoui, P. Piseri, L. Ravagnan
Università degli Studi di Milano, Milano
- M. Coreno
CNR - IMIP, Trieste
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UV absorption from carbon nanoparticles is a very interesting astrophysical topic. The prominent hump centered at 217.5nm is the most dominant feature in the interstellar extinction curve and also the most controversial and a long-standing problem in astrophysics. Actual models lack of experimental data about carbon dust in gas phase. At the University of Milano an experimental set-up based on a PulsedμPlasma Source has been developed for the investigation of free clusters at the Elettra Gas Phase beamline (CESyRA: Cluster Experiments with Synctrotron RAdiation). The cluster source produces very intense cluster beams with tunable size distribution. The design of the apparatus is extended with a chamber for gas phase reaction (water vapor, CO, H2…) providing a unique opportunity to study the gas phase properties of carbonaceous particles in different environment. We plan to investigate Resonant Raman scattering of free carbon particles tuning the high brilliance UV/VIS storage ring FEL of ELETTRA across the region of 217nm where the UV absorption hump in astrophysical data is observed and where a number of electronic transitions exist for variable size linear carbon chains.
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