FEL2012 - List of Authors (Spampinati, S.)

Paper

Title

Page

First Lasing of FERMI FEL-2 (1° Stage) and FERMI FEL-1 Recent Results

13

L. Giannessi, E. Allaria, L. Badano, D. Castronovo, P. Cinquegrana, P. Craievich, G. D'Auria, M.B. Danailov, A.A. Demidovich, S. Di Mitri, B. Diviacco, W.M. Fawley, E. Ferrari, L. Fröhlich, G. Gaio, R. Ivanov, E. Karantzoulis, B. Mahieu, N. Mahne, I. Nikolov, G. Penco, L. Raimondi, C. Serpico, P. Sigalotti, S. Spampinati, C. Spezzani, M. Svandrlik, C. Svetina, M. Trovò, M. Veronese, D. Zangrando, M. Zangrando
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
G. De Ninno
University of Nova Gorica, Nova Gorica, Slovenia
F. Parmigiani
Università degli Studi di Trieste, Trieste, Italy

The FERMI@Elettra seeded Free Electron Laser (FEL) is based on two complementary FEL lines, FEL-1 and FEL-2. FEL-1 is a single stage cascaded FEL delivering light in the 80-20nm wavelength range, while FEL-2 is a double stage cascaded FEL where the additional stage should extend the frequency up-conversion to the spectral range of 20-4nm. The FEL-1 beam line is in operation since the end of 2010, with user experiments carried on in 2011 and 2012. During 2012 the commissioning of the FEL-2 beam line has started and the first observation of coherent light from the first stage of the cascade has been demonstrated. In the meanwhile the commissioning of a number of key components of FERMI, as the laser heater, the X-Band cavity for the longitudinal phase space linearization and the high energy RF deflector has been completed. The additional control on the longitudinal phase space and a progressive improvement in the machine optics optimization had a significant impact of FEL-1 performances, which has reached the expected specifications. In addition, emission of radiation at very high order conversion factors (up to 29th) has been observed and double stage cascades have been preliminarily tested with the observation of coherent radiation in the water window, up to the 65th harmonic of the seed laser, at about 4 nm.

Slides MOOB06 [6.633 MB]

MOPD58

Commissioning of the FERMI@ELETTRA Laser Heater

177

S. Spampinati, E. Allaria, L. Badano, S. Bassanese, D. Castronovo, M.B. Danailov, A.A. Demidovich, S. Di Mitri, B. Diviacco, W.M. Fawley, L. Giannessi, G. Penco, C. Spezzani, M. Trovò
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
G. De Ninno, E. Ferrari
University of Nova Gorica, Nova Gorica, Slovenia

The linac of the FERMI seeded free electron laser includes a laser heater to control the longitudinal microbunching instability, which otherwise is expected to degrade the quality of high brightness electron beam sufficiently to reduce the FEL power. The laser heater consists of an short undulator located in a small magnetic chicane through which an external laser pulse enters to the electron beam both temporally and spatially. The resulting interaction within the undulator produces an energy modulation of the electron beam on the scale of the optical wavelength. This modulation together with the effective R52 transport term of the chicane increases the incoherent energy spread (i.e., e-beam heating). We present the first commissioning results of this system and its impact on the electron density and energy distribution and on FEL output quality.

TUOA04

Coherence Properties of FERMI@Elettra

B. Mahieu, E. Allaria, G. De Ninno, E. Ferrari, F. Parmigiani, L. Raimondi, S. Spampinati, C. Spezzani, C. Svetina, M. Zangrando
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
B. Mahieu
CEA/DSM/DRECAM/SPAM, Gif-sur-Yvette, France

We report the results of a campaign of measurements aimed at characterizing the spatial and temporal coherence of the FERMI@Elettra free-electron laser. The results (the first obtained on a high-gain seeded single-pass free-electron laser), are compared with those obtained on other (SASE-based) facilities.

Slides TUOA04 [3.274 MB]

TUOAI02

Hard X-ray Self-Seeding at the LCLS

R.R. Lindberg, W. Berg, D. Shu, Yu. Shvyd'ko, S. Stoupin, E. Trakhtenberg, A. Zholents
ANL, Argonne, USA
J.W. Amann, F.-J. Decker, Y.T. Ding, Y. Feng, J.C. Frisch, D. Fritz, J.B. Hastings, Z. Huang, J. Krzywinski, H. Loos, A.A. Lutman, H.-D. Nuhn, D.F. Ratner, J.A. Rzepiela, D.R. Walz, J.J. Welch, J. Wu, D. Zhu
SLAC, Menlo Park, California, USA
V.D. Blank, S. Terentiev
TISNCM, Troitsk, Russia
P. Emma
LBNL, Berkeley, California, USA
S. Spampinati
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy

Funding: U.S. Dept. of Energy Office of Sciences under Contract No. DE-AC02-06CH11357
The Linac Coherent Light Source (LCLS) has produced extremely bright hard x-ray pulses using self-amplified spontaneous emission (SASE) since 2009. In SASE, the electron beam shot noise initiates the FEL gain, resulting in output radiation characterized by poor temporal coherence and a fluctuating spectrum whose normalized width is given by the FEL bandwidth. Recently, colleagues at DESY suggested a self-seeding scheme for the LCLS to reduce the bandwidth*. Here, the SASE produced in the first half of the undulator line is put through a simple diamond-based monochromator; the resulting monochromatic light trailing the main SASE pulse is used to seed the FEL interaction in the downstream undulators. We report on the experimental results implementing such a scheme at the LCLS, in which we have measured a reduction in bandwidth by a factor of 40-50 from that of SASE at 8-9 keV. The self-seeded FEL operates close to saturation, with the maximum output energy approximately equal to that with no seeding for low charge. The observed level of power fluctuations in the seeded output is presently rather large, and future plans focus on discovering their origins and reducing their magnitude.
* Geloni, V. Kocharyan ,and E.L. Saldin, DESY 10-133, arXiv:10⁰⁸.3036 (2010)

Slides TUOAI02 [22.104 MB]

WEPD20

Time-Sliced Emittance and Energy Spread Measurements at FERMI@Elettra

417

G. Penco, E. Allaria, P. Craievich, G. De Ninno, S. Di Mitri, W.M. Fawley, E. Ferrari, L. Giannessi, C. Spezzani, M. Trovò
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
S. Spampinati
SLAC, Menlo Park, California, USA

FERMI@Elettra is a single pass seeded FEL based on the high gain harmonic generation scheme, producing intense photon pulses at short wavelengths. For that, a high-brightness electron beam is required, with a small uncorrelated energy spread. In this paper, we present a detailed campaign of measurements aimed at characterizing the electron-beam time-sliced emittance and energy spread, both after the first magnetic compressor and at the end of the linac.

TUOB02

Spectral Characterization of the FERMI Pulses in the Presence of Electron-beam Phase-space Modulations

213

E. Allaria, S. Di Mitri, W.M. Fawley, E. Ferrari, L. Fröhlich, L. Giannessi, B. Mahieu, G. Penco, C. Spezzani, M. Trovò
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
G. De Ninno, S. Spampinati
University of Nova Gorica, Nova Gorica, Slovenia

As a seeded FEL based on a single stage HGHG configuration, FERMI's FEL-1 has produced very narrow bandwidth FEL pulses in the XUV wavelength region relative to those typical of SASE devices. This important feature of seeded FELs relies however upon the capability to produce high quality electron beams and with clean longitudinal phase spaces. As has been predicted previously, the FEL output spectra can be modified from a simple, nearly transform-limited single spike by modulation and distortions of the longitudinal phase space of the electron beam. In this work we report a study of the FEL spectra recorded at FERMI for various situations showing the effects of phase-space modulation on the FEL properties.

Slides TUOB02 [4.376 MB]

Paper	Title	Page
MOOB06	First Lasing of FERMI FEL-2 (1° Stage) and FERMI FEL-1 Recent Results	13
	L. Giannessi, E. Allaria, L. Badano, D. Castronovo, P. Cinquegrana, P. Craievich, G. D'Auria, M.B. Danailov, A.A. Demidovich, S. Di Mitri, B. Diviacco, W.M. Fawley, E. Ferrari, L. Fröhlich, G. Gaio, R. Ivanov, E. Karantzoulis, B. Mahieu, N. Mahne, I. Nikolov, G. Penco, L. Raimondi, C. Serpico, P. Sigalotti, S. Spampinati, C. Spezzani, M. Svandrlik, C. Svetina, M. Trovò, M. Veronese, D. Zangrando, M. Zangrando Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy G. De Ninno University of Nova Gorica, Nova Gorica, Slovenia F. Parmigiani Università degli Studi di Trieste, Trieste, Italy
	The FERMI@Elettra seeded Free Electron Laser (FEL) is based on two complementary FEL lines, FEL-1 and FEL-2. FEL-1 is a single stage cascaded FEL delivering light in the 80-20nm wavelength range, while FEL-2 is a double stage cascaded FEL where the additional stage should extend the frequency up-conversion to the spectral range of 20-4nm. The FEL-1 beam line is in operation since the end of 2010, with user experiments carried on in 2011 and 2012. During 2012 the commissioning of the FEL-2 beam line has started and the first observation of coherent light from the first stage of the cascade has been demonstrated. In the meanwhile the commissioning of a number of key components of FERMI, as the laser heater, the X-Band cavity for the longitudinal phase space linearization and the high energy RF deflector has been completed. The additional control on the longitudinal phase space and a progressive improvement in the machine optics optimization had a significant impact of FEL-1 performances, which has reached the expected specifications. In addition, emission of radiation at very high order conversion factors (up to 29th) has been observed and double stage cascades have been preliminarily tested with the observation of coherent radiation in the water window, up to the 65th harmonic of the seed laser, at about 4 nm.
	Slides MOOB06 [6.633 MB]

MOPD58	Commissioning of the FERMI@ELETTRA Laser Heater	177
	S. Spampinati, E. Allaria, L. Badano, S. Bassanese, D. Castronovo, M.B. Danailov, A.A. Demidovich, S. Di Mitri, B. Diviacco, W.M. Fawley, L. Giannessi, G. Penco, C. Spezzani, M. Trovò Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy G. De Ninno, E. Ferrari University of Nova Gorica, Nova Gorica, Slovenia
	The linac of the FERMI seeded free electron laser includes a laser heater to control the longitudinal microbunching instability, which otherwise is expected to degrade the quality of high brightness electron beam sufficiently to reduce the FEL power. The laser heater consists of an short undulator located in a small magnetic chicane through which an external laser pulse enters to the electron beam both temporally and spatially. The resulting interaction within the undulator produces an energy modulation of the electron beam on the scale of the optical wavelength. This modulation together with the effective R52 transport term of the chicane increases the incoherent energy spread (i.e., e-beam heating). We present the first commissioning results of this system and its impact on the electron density and energy distribution and on FEL output quality.

TUOA04	Coherence Properties of FERMI@Elettra
	B. Mahieu, E. Allaria, G. De Ninno, E. Ferrari, F. Parmigiani, L. Raimondi, S. Spampinati, C. Spezzani, C. Svetina, M. Zangrando Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy B. Mahieu CEA/DSM/DRECAM/SPAM, Gif-sur-Yvette, France
	We report the results of a campaign of measurements aimed at characterizing the spatial and temporal coherence of the FERMI@Elettra free-electron laser. The results (the first obtained on a high-gain seeded single-pass free-electron laser), are compared with those obtained on other (SASE-based) facilities.
	Slides TUOA04 [3.274 MB]

TUOAI02	Hard X-ray Self-Seeding at the LCLS
	R.R. Lindberg, W. Berg, D. Shu, Yu. Shvyd'ko, S. Stoupin, E. Trakhtenberg, A. Zholents ANL, Argonne, USA J.W. Amann, F.-J. Decker, Y.T. Ding, Y. Feng, J.C. Frisch, D. Fritz, J.B. Hastings, Z. Huang, J. Krzywinski, H. Loos, A.A. Lutman, H.-D. Nuhn, D.F. Ratner, J.A. Rzepiela, D.R. Walz, J.J. Welch, J. Wu, D. Zhu SLAC, Menlo Park, California, USA V.D. Blank, S. Terentiev TISNCM, Troitsk, Russia P. Emma LBNL, Berkeley, California, USA S. Spampinati Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
	Funding: U.S. Dept. of Energy Office of Sciences under Contract No. DE-AC02-06CH11357 The Linac Coherent Light Source (LCLS) has produced extremely bright hard x-ray pulses using self-amplified spontaneous emission (SASE) since 2009. In SASE, the electron beam shot noise initiates the FEL gain, resulting in output radiation characterized by poor temporal coherence and a fluctuating spectrum whose normalized width is given by the FEL bandwidth. Recently, colleagues at DESY suggested a self-seeding scheme for the LCLS to reduce the bandwidth. Here, the SASE produced in the first half of the undulator line is put through a simple diamond-based monochromator; the resulting monochromatic light trailing the main SASE pulse is used to seed the FEL interaction in the downstream undulators. We report on the experimental results implementing such a scheme at the LCLS, in which we have measured a reduction in bandwidth by a factor of 40-50 from that of SASE at 8-9 keV. The self-seeded FEL operates close to saturation, with the maximum output energy approximately equal to that with no seeding for low charge. The observed level of power fluctuations in the seeded output is presently rather large, and future plans focus on discovering their origins and reducing their magnitude. Geloni, V. Kocharyan ,and E.L. Saldin, DESY 10-133, arXiv:10⁰⁸.3036 (2010)
	Slides TUOAI02 [22.104 MB]

WEPD20	Time-Sliced Emittance and Energy Spread Measurements at FERMI@Elettra	417
	G. Penco, E. Allaria, P. Craievich, G. De Ninno, S. Di Mitri, W.M. Fawley, E. Ferrari, L. Giannessi, C. Spezzani, M. Trovò Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy S. Spampinati SLAC, Menlo Park, California, USA
	FERMI@Elettra is a single pass seeded FEL based on the high gain harmonic generation scheme, producing intense photon pulses at short wavelengths. For that, a high-brightness electron beam is required, with a small uncorrelated energy spread. In this paper, we present a detailed campaign of measurements aimed at characterizing the electron-beam time-sliced emittance and energy spread, both after the first magnetic compressor and at the end of the linac.

TUOB02	Spectral Characterization of the FERMI Pulses in the Presence of Electron-beam Phase-space Modulations	213
	E. Allaria, S. Di Mitri, W.M. Fawley, E. Ferrari, L. Fröhlich, L. Giannessi, B. Mahieu, G. Penco, C. Spezzani, M. Trovò Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy G. De Ninno, S. Spampinati University of Nova Gorica, Nova Gorica, Slovenia
	As a seeded FEL based on a single stage HGHG configuration, FERMI's FEL-1 has produced very narrow bandwidth FEL pulses in the XUV wavelength region relative to those typical of SASE devices. This important feature of seeded FELs relies however upon the capability to produce high quality electron beams and with clean longitudinal phase spaces. As has been predicted previously, the FEL output spectra can be modified from a simple, nearly transform-limited single spike by modulation and distortions of the longitudinal phase space of the electron beam. In this work we report a study of the FEL spectra recorded at FERMI for various situations showing the effects of phase-space modulation on the FEL properties.
	Slides TUOB02 [4.376 MB]